


















THE PROSPECTOR’S 


FIELD-BOOK AND GUIDE. 


We also publish : 

Jl Practical Manual of Minerals, Mines 
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Illustrated by 171 Engravings. Second Edition. 
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New, Revised and Greatly Enlarged Edition, 
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Chemistry Simplified. A Course of Lectures 
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$2,25 




THE PROSPECTOR’S 


FIELD-BOOK AND GUIDE 


IN THE 

| 

SEARCH FOR AND THE EASY DETERMINATION OF 
ORES AND OTHER USEFUL MINERALS. 


BY 

Prof. H. S. OSBORN, LL.D., 

u 

AUTHOR OF “THE METALLURGY OF IRON AND STEEL,” “ A PRACTICAL MANUAL 
OF MINERALS, MINES, AND MINING.” 


ILLUSTRATED BY SIXTY-SIX ENGRAVINGS. 


EIGHTH EDITION, THOROUGHLY REVISED AND ENLARGED. 


PHILADELPHIA: 

HENRY CAREY BAIRD & CO, 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 

810 WALNUT STREET. 

1910. 



Copyright by 

HENRY CAREY BAIRD & CO. 
1910. 



Printed by the 

WICKERSHAM PRINTING COMPANY 
111-117 East Chestnut Street, 
Lancaster, Pa., U. S. A. 


©GI.A268410 



PREFACE TO THE EIGHTH EDITION. 


The remarkable sale of seven editions of The 
Prospector’s Field-Book and Guide, unmistak¬ 
ably indicating the firm hold which it has on the 
confidence of Prospectors, has rendered necessary 
the preparation ot this, the eighth edition. In 
doing this, the book has been carefully revised 
throughout, and where considered desirable, it has 
been enlarged. These revisions and amplifications 
add greatly, as it is believed, to the value and use¬ 
fulness of the volume, and bring it fully up to date. 

The work of revision has been undertaken by the 
same competent hand that so satisfactorily edited 
the second, third, fourth, fifth, sixth and seventh 
editions. As now presented to the public, it is felt 
to be a complete and thoroughly reliable guide and 
companion to the intelligent and enterprising 
searcher after ores and other useful minerals, in¬ 
cluding gems and gem-stones; the very best that 
has ever been published in any language. It has 
been provided with a thorough Table of Contents 
and an Index, rendering reference to any subject 
in it prompt and easy. 

In conclusion the publishers would add that this 

(V) 




Vi PREFACE TO THE EIGHTH EDITION. 

edition is in number more than twice as large as 
the first edition, and that the book now leads the 
entire literature of this important subject through¬ 
out the world ; and the reason for this leadership is 
not far to seek. With each new issue the type has 
been set up anew from title to the last page of index. 
Thus no new issue has been an exact reprint of a 
previous one, and thereby the book has always been 
up-to-date on day of publication. In the long ex¬ 
perience of the publishers covering a period of over 
three score years, they have never known the type 
of any other book to be set up throughout eight 
times as has been done with The Prospector’s 
Field-Book and Guide. 


Philadelphia, 1910. 


H. C. B. 


PUBLISHER’S PREFACE TO THE SECOND EDITION. 


The death of Dr. Osborn, two years ago, renders 
it necessary that the Publisher should prepare the 
preface to this revised edition of The Prospector’s 
Field-Book and Guide. 

The fact of a second edition of this book having 
been called for so soon after the publication of the 
large first edition, justifies the belief that it has 
supplied a public requirement. The task of revis¬ 
ing the work has devolved upon thoroughly com¬ 
petent hands; and whilst it has been aimed, by the 
insertion of further information regarding the sub¬ 
jects treated in the original edition, to make it still 
more acceptable to those for whom it was prepared, 
a new chapter has also been added on Petroleum, 
Ozocerite, Asphalt and Peat, together with a Glos¬ 
sary of Terms used in prospecting, mining, miner¬ 
alogy, geology, etc. 

While the work of revision has been done with 
conscientious care, under the supervision of the 
Publisher, it can hardly be hoped that it has been 
so well done as if Dr. Osborn, with his profound 
knowledge of the subject treated, had been alive to 
direct it for himself, and in his own manner. 

( vii) 



viii publisher’s preface to second edition. 

Henry Stafford Osborn was born in Philadelphia, 
August 17, 1823, and died in New York City, Feb¬ 
ruary 2, 1894. He was graduated at the Univer¬ 
sity of Pennsylvania in 1841; went abroad in 1843 
or 1844 ; studied at Bonn, Germany, and at the 
Polytechnic Institution of London. Before the 
civil war he held the chair of Natural Science at 
Roanoke College, Va., and in 1866 accepted a pro¬ 
fessorship at Lafayette College, Easton, Pa. Leav¬ 
ing Lafayette in 1870, he became, in 1871, Pro¬ 
fessor in Miami University at Oxford, Ohio. In 
1865 he received from Lafayette College the degree 
of LL. D. 

In 1869 he published “The Metallurgy of Iron 
and Steel;” in 1888, “A Practical Manual of Min¬ 
erals, Mines and Mining;” in 1892, the first edition 
of The Prospector’s Field-Book and Guide, the 
success of all of which books has been pronounced. 

Personally, Dr. Osborn was charming, full of in¬ 
formation on a wide range of subjects, which he 
had studied thoroughly ; enthusiastic, amiable and 
just; and the relations of his publisher with him 
during a quarter of a century will ever be among 
the brightest and best recollections of that pub¬ 
lisher’s long career in business. 

HENRY CAREY BAIRD. 

Philadelphia, January 15, 1896. 


PREFACE TO THE FIRST EDITION, 


In the following pages we have attempted to 
present such a view of the whole subject of pros¬ 
pecting for the useful minerals that any liberally 
educated reader may fully comprehend our mean¬ 
ing. We have therefore explained special terms 
where we have thought it convenient to use them, 
and where the technically educated student would 
not need an explanation. 

It must be understood that the subjects of chem¬ 
istry, mineralogy, and metallurgy are introduced 
only for their practical bearing upon the ores in 
hand, or those sought for, and not for theory, or 
the philosophy of the operation, much as such 
theory or philosophy would please and instruct. 
The prospector must, therefore, refer to larger works 
if he desire to be instructed in the principles gov¬ 
erning the sciences, the teachings of which we have 
frequently made use of. 

We would suggest to any one intending to use 
this volume for practical work, to become ac¬ 
quainted with the whole book before attempting to 
use any special part alone. The object and con¬ 
struction have made it necessary to treat some 
(ix) 



X 


PREFACE TO THE FIRST EDITION. 


special topics without repeating principles and 
methods already given in some part of the work, 
but which bear some relation to the topic under 
immediate consideration. 

The Table of Contents and Index have both been 
carefully prepared, and being very full, will make 
reference to any subject in the volume easy and 
satisfactory. 

Oxford, Ohio, Jan. 5, 1892. 


CONTENTS. 


CHAPTER I. 

PRELIMINARY INSTRUCTION. 

PAGE 

Disappointment and loss caused by lack of knowledge by 

prospectors. 1 

Technical mineralogy, the first study of the prospector; Defini¬ 
tion of a mineral; Definition of rocks; Principal constituents 

of rocks.2 

Quartz and its varieties; Feldspar ...... 3 

Most important varieties of feldspar.4 

Micas and most important species of them .... 5 

Amphibole, often called hornblende, and its most important 
varieties .......... 7 

Pyroxene, including augite ....... 8 

Chlorite; Talc .......... 10 

Serpentine; Elementary composition of minerals; Calculation of 
the amounts of the elements going to make up any given 
mass ........... 11 

Classes of substances; Definition of acids, bases and salts; Ex¬ 
amples of minerals which are salts, and of basic minerals; 
Silicates .......... 12 

Colors of minerals; Effect of the intermixing of coloring matter. 13 
Products of the distribution of accidental colors; Polychroism . 14 

Phosphorescence; Colors and forms under which native minerals 
may appear .......... 15 

Cleavage . . . . . . . . . . .16 

Fracture; Streak; Hardness . . . . . . .17 

Scale of hardness; Manner of testing the hardness of a mineral. 18 

Flexibility and elasticity; Smell.19 

Taste; Malleability; Ductility ....... 20 

Luster; Definition of the various kinds of luster . . .21 

(xi) 





Xll 


CONTENTS. 


PAGE 


Fusibility; Specific gravity; Definition of specific gravity; Rule 
for finding the specific gravity ...... 22 

Mode of arriving at a rough idea of the specific gravity of 
minerals .......... 24 

Weight and form of minerals ....... 25 

Importance of a knowledge of the characteristics of the rocks 
associated with minerals ....... 26 

Desirability of a general knowledge of the manner in which the 
geologic rocks are laid down; Signs by which the names of 
the sedimentary rocks may be determined . . . .27 

Horizons of rocks; Movements of the earth’s crust illustrated by 
a section showing contorted strata due to lateral pressure; 
Practical geology; Horizons sterile in ore . . . .28 

Horizons in the United States which abound in the useful metals; 

Classification of rocks; Definition of a rock . . . .29 

General sameness in the geological horizons throughout the 
world; Table showing the relations of certain rocks, one to 
another; Igneous rocks ........ 30 

Metamorphic rocks.32 

Aqueous rocks; Sandstone, described and illustrated. . . 33 

Shale, described and illustrated; Granite, and varieties of it . 34 

Granite with black mica and feldspar crystals, described and 
illustrated; Changes to which the rocks have been subjected 
since their formation ........ 35 

Faults; Anticlinal and synclinal; Strike and dip of a rock. . 36 

First indications of a deposit possessing economic value; Where 
metalliferous deposits should be looked for; Mode of occur¬ 
rence of the valuable mineral and metal-bearing deposits . 37 

Lodes ........... 38 

Hanging wall; Foot wall; Underlie; Country; Formations or 
horse; Casing; Testing an outcrop of mineral . . .39 

Selection of the point for sinking a shaft . . . . .40 

Mode of measuring up quartz; Tendency of minerals to decom¬ 
pose when exposed to the action of the weather . . .41 

Beds and layers; Irregular deposits ...... 42 

Surface deposits; Selection of a spot for starting actual prospect¬ 
ing operations.43 

Auriferous lodes and their most likely localities; Source of gold 
in the right-hand branch of a forked river . . . .44 



CONTENTS. 


Xlll 


PAGE 


Spots upon which the sun shines before noon richest in metals; 
Explanation of this theory; The color of the rocks as a guide 

to the prospector .45 

Necessity of paying attention to the wash of rivers and creeks; 
Pilot stones .......... 46 

Placers and placer gold; Character of placer deposits ; . 47 

Testing alluvial deposits .48 

Forms of alluvial deposits, described and illustrated . . .49 

Estimating the value of alluvial claims; Beach placers . . 51 

Indicative plants; Vegetation indicative of lead, iron, limestone 
and phosphate ......... 52 

Vegetation indicative of silver and zinc; Hints in looking for 
indications where superficial deposits are known to occur . 53 

Mode of occurrence of gold in Australia and in California; 
Occurrence of other minerals in alluvial deposits; Points to be 
observed in examining a lode; Table showing the association 
of ore in metalliferous veins ..54 


CHAPTER II. 

THE BLOW-PIPE AND ITS USES. 

On what chemical tests for minerals depend; Illustrations of the 


character of changes brought about by chemical tests . . 56 

Requirements for blow-pipe practice; Preparation of dry car¬ 
bonate of soda ......... 57 

Borax and other supplies; Mode of using the blow-pipe . .58 

Practice with the blow-pipe by blowing upon a piece of char¬ 
coal; Colors of a candle flame; Oxidizing and reducing flames, 
described and illustrated ....... 59 

Roasting; Practical illustration showing the characteristic power 
of either flame; Mode of making a platinum wire loop, de¬ 
scribed and illustrated ........ 61 

How to make a blow-pipe. ....... 62 

Principal means of chemically testing minerals before the blow¬ 
pipe; Blow-pipe experiments; Recognition of the presence of 
metals by the color imparted to the fused borax . . . .63 

Table of color indications ........ 64 

Mode of testing with carbonate of soda on charcoal . . .65 

Observations and inferences which may result from the above 
test; Test for sulphur and arsenic.66 





XIV 


CONTENTS. 


PAGE 

Test for mercury, antimony and other substances; Test in glass 
tubes ........... 67 


CHAPTER III. 

CRYSTALLOGRAPHY. 

The composition of many minerals indicated by their forms; 

Classes or systems of crystalline forms; Isometric system . 69 
The cube, described and illustrated; Varieties of the cube. . 70 

The octahedron and dodecahedron, described and illustrated; 

Tetragonal system. . . . . . . . .71 

The prism, described and illustrated; The zircon or jacinth, 
described and illustrated; Hexagonal system . . . .72 

Forms of the hexagonal system, described and illustrated . .73 

Orthorhombic system . . . . . . . .74 

Monoclinic system; Triclinic or thrice-inclined system; Illustra¬ 
tions of the different systems of crystallization . . .75 

Distinction between the turquois, lazulite and lapiz lazuli. . 76 


CHAPTER IV. 

SURVEYING. 

To measure heights which are inaccessible. . . . .77 

To measure areas, illustrated by examples. . . . .79 

To measure an inaccessible line. ..... .82 

The prism compass and its uses. ...... 84 


CHAPTEE V. 

ANALYSES OF ORES. 

Kinds of analysis employed; Preliminary examinations; Detec¬ 
tion of sulphur, arsenic and selenium; Indications of iron and 
silver ........... 86 

Determination of native gold and silver; Indication of copper; 
Detection of antimony and tin, manganese, alumina, mag¬ 
nesia, lime and zinc ........ 87 

Determination of cobalt and nickel, uranium, titanium, vana¬ 
dium and mercury.88 

Examination of sandstone; Wet method of analysis and direc¬ 
tions for its execution ........ 89 

Indication of lead and mercury in the assay . . . .92 



CONTENTS. 


XV 


PAGE 

Apparatus for making hydrogen sulphide, described and illus¬ 
trated . 93 

The filtrate and its examination ...... 94 

What the precipitate may contain; Treatment of the precipitate; 

Precipitation of chromium oxide. 95 

Precipitation of alumina; Definition of an excess . . .96 

Precipitation of manganese, cobalt and nickel . . . .97 

Establishment of the presence of mercury oxide and lead sul¬ 
phate .98 

Indications of bismuth and cadmium, of copper and of sulphur. 99 
Indications of gold, platinum, arsenic, and antimony . . 100 

Indication of tin; Dry assay of ores; Crucibles; Scorifiers. . 101 

The cupel; The muffle; An assay furnace, described and illus¬ 
trated . 102 

Brasquing; Portable assay furnace for field testing; Mode of 
obtaining the amount of an ordinary metal in an ore . . 103 

Scales, weights, etc.; Assay ton weights.104 

Sampling and pulverizing; Selection of a sample of the mineral. 105 

Testing gold and silver ores; Cupellation.106 

Flux for melting the ore in a crucible . . . . .107 

Processes for assaying gold quartz ...... 108 

Cupel stains by which the presence of metals in the ore is indi¬ 
cated; Testing of lead ore; Mode of ascertaining the amount 
of lead in galena ......... 109 

Testing copper ore, ores of tin, mercury and antimony . .110 

Testing ores of bismuth, zinc, manganese, nickel and cobalt; 
Directions for making a fire lute . . . . . .111 

CHAPTER VI. 

Special Mineralogy, 
gold. 

Importance of studying minerals from actual specimens; Distri¬ 
bution of gold ......... 112 

Chief gold-producing localities; Principal mode of occurrence 
of gold; Composition of gold in the metallic state . . .113 

Mexican rhodium gold; Gold amalgam; Black gold; Bismuth 
gold; To detect a content of native gold in pyrites; Crystalli¬ 
zation of gold; Gold crystals, illustrated . . . .114 





XVI 


CONTENTS. 


PAGE 

Large lump of gold found at Forest Creek, Victoria, Australia; 

Physical properties of gold; Variations in the color of gold . 115 
Behavior of gold under the blow-pipe and towards acids . .116 

Instrument for the discovery of gold; The batea, described and 

illustrated.117 

Panning out and mode of procedure . . . . . .118 

Removal of the iron sand; Blowing . . . . . .119 

The cradle or rocker, described and illustrated . . . .120 

The long tom, described and illustrated . . . . .121 

Methods of recovering gold employed in Alaska . . .123 

Ground sluicing.124 

Sluices; Hydraulicking or hydraulic mining . . . .125 

Dredging; Conglomerate found on alluvial gold fields . .128 

Mode of saving the fine flour or float gold; Lode prospecting . 129 
Directions for making an amalgamating assay . . . .130 

Construction of a retort for the above purpose .... 131 

Darton’s gold test.132 

Variation of the above test; Occurrence of gold in other forms . 133 

Placer gold; Gold amalgam.134 

Geology of gold; Occurrence of gold in quartz; Original position 

of gold.135 

Quartz rocks; Mode of studying the character of the stone; 

Hungry quartz . . . . . . . . .136 

Gold in granite regions, illustrated by a section showing the two 
conditions under which gold is usually found in rock and 

drift.137 

Significance of an “ ironstone” blowout; Peculiar and seemingly 

irregular deposits of gold.138 

Origin of metamorphic rocks; Igneous rocks and their compo¬ 
sition ........... 139 

Composition of metamorphic granite; Where the most paying 
gold is found ......... 140 

Gold in combination; To separate gold in metallic sulphides, 

for instance, iron pyrites.141 

Mode of preparing fuming nitric acid.142 

Another method of detecting and separating the gold . . 143 

What constitutes profitable gold mining; Method of separating 

gold which gives very accurate results.145 

Rule for ascertaining the amount of gold in a lump of auriferous 
quartz.146 







CONTENTS. 


XVII 


CHAPTER VH. 

TELLURIUM, PLATINUM, SILVER. 

Tellurium and its properties; Tellurides.148 

The most important tellurides; Nagyagite, foliated or black 
tellurium; Hessite; Petzite ....... 149 

Sylvanite or graphic tellurium; Platinum, its occurrence and 

properties.150 

Sperrylite.152 

How to distinguish platinum; Chemical test of platinum; Sepa¬ 
ration of platinum from gold and other metals . . . 153 

Preparation of stannous chloride; Sperrylite .... 154 
Iridium; Osmium; Palladium; Silver; Native silver, its occur¬ 
rence and properties . . . . . . . .155 

Chemical test of silver . . . . . . . .156 

Derivation of most of the silver of commerce; Other forms in 
which silver is found; Silver sulphides; Silver glance or 

argentite.157 

Cerargyrite or horn silver. ......’. 158 

Stephanite or brittle silver ore; Ruby silver . . . .159 

Bromic silver or bromyrite; Valuing silver ore. . . . 160 


Argentiferous minerals; Test for the presence of silver in ores . 161 
Geology of silver, illustrated by sections across the Comstock 
Lode and surrounding strata, east and west and north and 


south, and showing the mines and the surfaces . . . 162 

Non-metallic substances of the Comstock Lode . . . .163 

Extent and value of the Comstock Lode; Geology of the Tono- 
pah district . . . . . . ‘ . . . . 165 

Occurrence of silver at the Eureka Mines, Nevada . . .167 

Geology of the Ruby Hill Mines; The Emma Mine, Utah; 
General geologic conditions in which silver ores are found . 168 

CHAPTER VIII. 

COPPER. 

Native copper, its occurrence and properties; Modes of testing 


minerals containing copper . . . . . . .170 

Natural combinations of copper; The more important ores of 
copper; Cuprite, red copper ore or ruby copper . . . 171 

Plush copper; Chalcocite, copper glance, or vitreous copper; 
Tetrahedrite or gray copper ore . . . . . .172 



XV111 


CONTENTS. 


PAGE 


Chalcopyrite or copper pyrites.173 

Peacock ore; Chrysocolla or silicate of copper . . . .174 

Black oxide of copper; Malachite or green carbonate of copper; 

Azurite or blue carbonate of copper . . . . .175 

Variegated copper ores, bornite or erubiscite . . . .176 

Ores which furnish the bulk of the world’s consumption of cop¬ 


per; Copper in Alaska; Geology of copper, illustrated by 
section of the copper bed at the Dolly Hide Mine, Maryland. 177 
Facts to be remembered to become ready in the detection of 


copper as an ore; Rocks with which copper is associated . 178 
Section of strata in the Lake Superior copper region; Section 
of the Eagle Vein, Lake Superior; Examination of specimens 

for copper.179 

Examination of the region in which copper ore is supposed to 
occur; To obtain the per cent, of copper in an ore. . . 180 

Precautions to be observed in the assay of copper . . .182 


CHAPTER IX. 


LEAD AND TIN. 

Lead; Occurrence of native lead; Most important lead ore; 
Galena. .......... 184 

Order of strata in the lead district of Wisconsin, Illinois and 
Iowa; Geology and form of lodes of the galena ores; Carbonate 
of lead, white lead ore, or cerussite . . . . .185 

Lead lode in micaceous slate in mine near Middletown, Conn.; 
Blow-pipe cupelling; Section of strata in California Gulch, 
Colorado .......... 186 

Sulphate of lead or anglesite; Phosphate of lead or pyromor- 

pbite.187 

Crocoite or chromate of lead; Massicot or lead ochre; Lead- 

antimony ores; Jamesonite.188 

Zincenite; Geology of lead illustrated by a section of galena 

limestone.189 

Circulation of water in lead veins.190 

Deposit of lead in a fissure of the limestone; Chief sources of 

lead in the United States; Tin.191 

Assay of tin ore; Cassiterite or tin stone.192 

Wood tin; Toad eye tin; Stream tin.193 



CONTENTS. 


XIX 


PAGE 

Discovery of tin in Banca and Billiton; Tin pyrite (sulphide of 
tin) .194 

Occurrence of cassiterite in the United States; Discoveiy of 
stream tin in Alaska . . . . . . . .195 

Deposits of tin at El Paso, Texas.196 

Cassiterite as a type of a strongly marked class of deposits; Min¬ 
erals most commonly associated with cassiterite . . .197 

Tin granites; Greisen; Minerals most commonly associated with 
tin; Wolframite ......... 198 


CHAPTER X. 

ZINC, IRON, MOLYBDENUM, TITANIUM, URANIUM, VANADIUM. 


Zinc; Smithsonite or zinc carbonate ...... 200 

Calamine or silicate of zinc; Zincite or red oxide of zinc; Sul¬ 
phide of zinc, sphalerite or zinc blende, also called black 
jack, false lead, false galena . . . . . . 201 

Geology of zinc, illustrated by a section of strata near Sparta, 

New Jersey Zinc Mines.. 202 

Deposits of sulphide of zinc in Colorado and Montana; Blow¬ 
pipe test for zinc; Iron; Native or meteoric iron . . . 203 


Masses of meteoric iron found at Disko, Greenland; Meteoric 


masses containing small black diamonds found in Arizona; 
Analyses of meteoric iron; Distinction of meteorites from 

metallic iron.204 

The most important ores of iron; Magnetite or magnetic iron 
ore; Usual geological position of magnetite .... 205 

Form in which iron exists in magnetite; Franklinite; Specular 
ore; Red hematite ........ 206 

Brown iron ore or brown hematite or limonite; Spathic iron ore 
or siderite .......... 207 

Black band ore; Chromic iron or chromite .... 208 

Iron pyrites; Arsenical pyrites or mispickel .... 209 

Geology of iron ores; Geological horizons around the iron ores 

of Lake Superior.210 

Section of Pilot Knob, Missouri . . . . . .211 

General geologic regions in which iron ores are to be found; 

Use of the magnetic needle in prospecting for iron; W. H. 
Scranton’s report on the subject ...... 212 

Method of using the compass in searching for ore . . .214 




XX 


CONTENTS. 


PAGE 

Molybdenum; Titanium; Rutile ...... 215 

Octahedrite; Brookite; Uranium.216 

Pitchblende or uraninite . . . . . . . .217 

Vanadium; Descloizite; Dechenite; Volborthite . . .218 

CHAPTER XI. 

MERCURY, BISMUTH, NICKEL, COBALT, AND CADMIUM. 
Mercury or quicksilver; Formation of amalgams; Native mer¬ 
cury .220 

Native amalgams; Selenide of mercury; Cinnabar or sulphide 
of mercury .......... 221 

Metacinnabarite; Guadalcazarite; Quicksilver deposits at 
Almaden, Spain; Occurrence of cinnabar at Idria, Austria . 222 
Quicksilver-bearing belt of California; Report on this subject 
by M. G. Rolland ........ 223 

Bismuth; Geology of bismuth; Nickel ..... 224 

Examination of nickel under the blowpipe; Chief ores of nickel; 

Smaltite; Nickel arsenide, copper nickel or nicolite . . 225 

Emerald nickel; Millerite; Sources of nickel in Sudbury, 
Canada .......... 226 

Foleyrite; Whartonite; Jack’s tin, or blueite .... 227 

Analysis of ores for nickel and cobalt; Separation of lead . . 228 

Separation of copper . . . . . . . 229 

Precipitation of the iron ........ 230 

Construction of a hydrogen apparatus, described and illustrated. 231 
Separation of nickel and cobalt ...... 234 

Gamierite; Cobalt; Smaltite ....... 236 

Cobaltite; Erythrite; Linnaeite ...... 237 

Earthy cobalt or cobalt wad (asbolite); Cadmium; Greenockite. 238 

CHAPTER XII. 

ALUMINIUM, ANTIMONY,- MANGANESE. 

Aluminium and its distribution; Minerals which serve as sources 
of the metal .......... 239 

Bauxite and its purification for the purpose of the aluminium 
manufacturer ......... 240 

Cryolite, its properties and uses ...... 241 

Antimony, and the forms in which it appears .... 242 

Stibnite, its properties and occurrence ..... 243 


CONTENTS. 


XXI 


PAGE 

Manganese; Classes of ores of manganese; Wad . . . 244 

Pyrolusite; Psilomelane.245 

Rhodocrosite or manganese carbonate; Location of the most 
important mines of manganese in the United States . . 246 

Uses of manganese ......... 247 


CHAPTER XIII. 


VARIOUS USEFUL MINERALS. 

Alum and its varieties; Apatite, phosphate of lime . . . 249 

Coprolites.250 

Principal use of apatite; Arsenic; Native arsenic . . . 251 

Realgar; Orpiment; Asbestos ....... 252 

Barytes or barium sulphate, or heavy spar; Witherite . . 253 

Borax; Deposits of borax in the United States . . . . 254 

Clays.255 

Classes of soft clays; Kaolin, porcelain clay or China clay; Pot¬ 
tery or plastic clay; Bole ....... 256 

Fuller’s earth; Coal; Coal formations.257 

Anthracite; Bituminous coal; Cannel coal; Brown coal or lignite. 258 
Jet; Dolomite; Feldspar, orthoclase. ..... 259 

Adularia;. Amazon stone; Flint; Fluorspar, fluorite. . . 260 

Graphite, plumbago, black lead ...... 261 

Varieties of graphite; Graphite in Ceylon; Graphitiferous rocks 
in Canada and the United States ...... 262 

Graphite deposits at Ticonderoga, New York, in Albany Co., 
Wyoming, and at Pitkins, Gunnison Co.; Test of the purity 
of graphite .......... 263 

Gypsum; Alabaster; Selenite; Satin spar; Plaster of Paris . 264 

Infusorial earth; Lithographic limestone.265 

Meerschaum or sepiolite; Micas ...... 266 

Biotite or black mica; Muscovite or white mica; Pegmatite; 

Nitre or saltpetre.267 

Chile saltpetre; Rock salt; Salt deposits in the United States . 268 
Superficial deposit of rock salt in Petit Anse Island, Louisiana. 269 

Slate; Sulphur. . . ..270 

Method of estimating the sulphur available in a sample of 

pyrites.271 

Talc or soapstone, or steatite.272 








XXII 


CONTENTS. 


PAGE 

CHAPTER XIV. 

GEMS AND PRECIOUS STONES. 

Occurrence of gems and precious stones in the United States; 

Comparatively little value of many gems . . . .273 

Associations of valuable specimens; Occurrence of diamonds and 
gold in the same alluvial deposit . . . . . .274 

Use of the dichroiscope in distinguishing gems . . .275 

Diamond; Occurrence of the diamond in India and Borneo . 277 
Diamonds in Brazil; Carbonado or black diamond; Minerals 
associated with the diamond in South Africa . . .278 

The diamond-bearing ground at the Kimberley mine, South 
Africa; Occurrence of diamonds in the Ural, in Australia, 

New Zealand, and the United States; First diamond found in 
this country .......... 279 

Natural surface of the diamond ...... 280 

Color of the diamond ; Black diamond; Properties of the 
diamond .......... 281 

Refractive power of the diamond; On what the value of a 
diamond depends; Some of the. largest diamonds, described 
and illustrated; The Koh-i-noor or mountain of light; The 

Orloff.282 

The Grand Duke of Tuscany or Florentine; The Pitt or Regent; 

The Hope; The Star of South Africa; The Victoria; The 
Excelsior or Jubilee ........ 284 

The Cullinan; Corundum, and its localities in the United States. 285 
Varieties of corundum ........ 286 

Properties of corundum; Emery; Sapphire, its properties and 
varieties. .......... 287 

Localities for sapphire in the United States; Ruby, its proper¬ 
ties and varieties.288 

Occurrence of ruby; Value of ruby; Difference between the 
garnet and the ruby ........ 289 

Topaz, its properties and varieties.290 

Occurrence of topaz; Beryl or emerald.291 

Occurrence of beryl in the United States and in Mexico; 
•Phenacite .......... 292 

Zircon;- Garnet ......... 293 

Tourmaline .......... 294 

Epidote; Opal.295 


CONTENTS. 


xxiii 

PAGE 

Varieties of opal; Localities for opal ..... 296 

Turquois; Agate.297 

Chalcedony .......... 298 

Carnelian; Chrysoprase; Jasper; Wood jasper; Bloodstone or 

heliotrope; Rock crystal ..299 

Amethyst; Rose quartz; Yellow quartz or citrine or false topaz. 300 
Smoky quartz or cairngorm; Onyx and sardonyx; Cat’s eye . 301 

List of gem stones known to occur in the United States . . 302 

List of species and varieties found in the United States, but not 

met with in gem form; List of species and varieties not yet 
identified in any form in the United States; List of gem stones 

occurring only in the United States.303 

Table of characteristics of gems. ..304 

CHAPTER XV. 

PETROLEUM, OZOCERITE, ASPHALT, PEAT. 

Occurrence of crude petroleum in various parts of the United 

States . . . ..307 

Properties of crude petroleum; Outfit and best time of the year 
for prospecting; Examination of an iridescent film on the sur¬ 
face of water; Indication of the presence of oil . . 309 

Tracing the sources of the oil; The water test . . . .310 

Fresh fracture of oil-bearing sandstone; Tracing an erratic block 
of oil-bearing sandstone. . . . . . . . 311 

Color of traces of oil upon the surface of water in cooler weather; 
Iridescent films in swampy puddles; Salses (mud volcanos) 
and exhalation of natural gas as an indication of petroleum . 312 
Occurrence of the oil in definite geological horizons; Occurrence 
of oil in beds and veins; Tracing a thick seam or stratum of 
oil-bearing sandstone ........ 313 

Outcrops in a large mass of sandstone; Data to be made in the 
sketch-map when promising outcrops of oil have been found, 

illustrated.. 314 

Vein-like occurrence of oil, described and illustrated. . . 316 

Quality of the oil; Ozocerite and its occurrence; Deposit of ozo¬ 
cerite in Galicia, Austria, described and illustrated . .318 

Retinite; Elaterite or elastic bitumen; Pyropissite; Properties of 

ozocerite i.319 

Native asphalt or bitumen; Most remarkable deposit of asphalt. 320 





XXIV 


CONTENTS. 


PAGE 

Asphalt in California and other localities in the United States; 

Peat.321 

APPENDIX. 

Prospecting by means of electricity ...... 323 

Weights and Measures.. . 325 

English length; Particular measures of length; Surface measure. 326 
Surface measure in feet; Solid measure; Troy weight; Avoirdu¬ 
pois weight; Weight by specific gravity; Method of finding 
the weight of masses without the use of scales . . .327 

Special weights, etc. . . . . . . . . 329 

French measures; Length; Surface ...... 330 

Solid measure; Weight; Specific gravity of metals, ores, rocks, 
etc.; Ores associated with gold and silver . . . .331 

Other ores; Minerals of common occurrence .... 332 

Average in cubic feet of a ton weight of various materials; Assay 
of gold by the touchstone ....... 333 

Estimation of gold in alloys.335 

Standard values of gold in different countries; Power for mills . 336 
Boring; Weight of hammers used for different sizes of boring 

( bars.337 

Diamond drill.338 

Table of the chemical elements, their symbols, atomic weights 
and specific gravities ........ 339 

To find the proportional parts by weight of the elements of any 
substance whose chemical formula is known; Common names 
of chemical substances ........ 341 

Prospectors’ pointers ........ 343 

Glossary of terms used in connection with prospecting, mining, 

geology, etc.345 

Index.365 







THE 


PROSPECTOR’S FIELD-BOOK AND GUIDE. 


CHAPTER I. 

PREPARATORY INSTRUCTION. 

It is well known that much disappointment and 
loss accrue through lack of knowledge by prospect¬ 
ors, who, with all their enterprise and energy, are 
often ignorant, not only of the probable locality, 
mode of occurrence and widely differing appearance 
of the various valuable minerals, but also of the 
best means of locating and testing the ores when 
found. It is a well established fact that most of 
the important mines of the world have been discov¬ 
ered by accident; and in many cases by people 
who have been quite ignorant and wholly unversed 
in the value of minerals. Many valuable discov¬ 
eries have been delayed, or, when made, abandoned 
as not paying from the same cause—ignorance of 
the rudiments of mineralogy and mining. Hence 
in preparation for skilled work, an accurate knowl¬ 
edge of the nature of ores and the ability to recog¬ 
nize those which are worthy of attention are of the 



2 prospector’s field-book and guide. 

utmost importance. Such knowledge places the 
prospector at a considerable advantage, and enables 
him to utilize chance discoveries made by others 
who are not so qualified. His very first study 
should therefore be that of 

TECHNICAL MINERALOGY. 

By a mineral is meant any chemically homogene¬ 
ous substance which neither forms, nor retains any 
traces of having formed, part of an organized body, 
and which has not been produced by the applica¬ 
tion of physical forces by man. The properties of 
minerals are numerous. Some, such as the form, 
bulk, hardness, color, etc., are readily perceived ; 
while others such as the chemical nature, crystalline 
structure, behavior towards light and heat, are not 
so apparent, and can only be determined by means 
of a systematic investigation. The value of these 
properties in affording distinguishing characters 
differs greatly, but the most important are chemical 
composition, crystalline form, and density. 

When two or more minerals occur together and 
form large masses, they constitute rocks. 

The minerals which are the principal constituents 
of rocks are the following : # 

1. Those containing silica: as quartz; the feld¬ 
spars ; the micas; hornblende ; pyroxene ; talc ; 
serpentine; chlorite. 

2. Carbonates: as carbonate of lime or calcite ; 
carbonate of lime and magnesia or dolomite. 

3. Sulphates: as sulphate of lime or gypsum. 


PREPARATORY INSTRUCTION. 


3 


The special characteristics of these, and of other 
less frequent mineral constituents may be learned 
from a text-book on mineralogy. The following are 
the prominent characters of the most common kinds 
concerning the prospector: 

Quartz. Occurs in crystals; also massive with 
a glassy luster. It is too hard to be scratched with 
a knife. It varies in color from white or colorless 
to black, and in transparency, from transparent 
quartz to opaque. It has no cleavage, that is, it 
breaks as easily in one direction as another like 
glass. 

There are many varieties of quartz, of which may 
be mentioned : Limpid quartz , clear and colorless; 
amethyst , violet crystals ; agate , presenting various 
colors arranged in parallel bands, straight, curved, 
or zigzag; chalcedony , transparent or translucent, 
and varying in color from white to gray, blue, 
brown and other shades; flint, massive, dark and 
dull color, edges translucent; hornstone, resembles 
flint, but differs from it in being more brittle, in 
breaking with a splintery, uneven fracture, and in 
not being so hard as quartz ; basanite, Lydian stone , 
or touchstone , velvety black, more opaque than horn- 
stone. It is used for trying the purity of gold. 

Opal is also a form of silica. 

Feldspar. This name is given to a group of 
minerals which are inferior to quartz only as a con¬ 
stituent of rocks. They have a luster nearly like 
quartz, but often somewhat pearly on smooth faces, 
are very nearly as hard as quartz, with about the 


4 prospector’s field-book and guide. 

same specific gravity (2.4 to 2.6); and in general 
have light colors, mostly white or flesh-colored, 
though occasionally dark-grey, brownish or green. 
They differ from quartz in having a perfect cleav¬ 
age in one direction, yielding under the hammer a 
smooth lustrous surface and another nearly as per¬ 
fect in a second direction inclined 84° to 90° to the 
first; also in being fusible before the blowpipe, 
though not easily so; also in composition, the feld¬ 
spars consisting of silica combined with alumina 
and an alkali—this alkali being either potash, soda, 
or lime, or two or all of them combined. Included 
in this group are a number of distinct kinds or 
species. These species differ in the proportion of 
silica (the acid) to the other ingredients (bases), and 
in the particular alkali (potash, soda, or lime) pre¬ 
dominating. 

The most important kinds are : 

Orthoclase, or common feldspar, a potash feldspar. 
The cleavages make a right angle with one another, 
whence the name, signifying cleaving at a right 
angle. 

In the following kinds the cleavages make a right 
angle with one another of 84° to 87° and hence 
they are sometimes called anorthic feldspars or 
plagioclastic feldspars. 

Albite, a soda feldspar, colorless and transparent, 
or translucent, and various shades of red, yellow, 
green and gray. 

Oligoclase, a soda-lime, the soda predominating. 
Color, generally whitish or grayish with shades of 
green and yellow. 


PREPARATORY INSTRUCTION. 


5 


Labradorite, a lime soda, often iridescent. Color, 
usually ash or greenish-gray, but frequently various 
shades of green, yellow, and red, and sometimes the 
smaller crystals are colorless. 

Anorthite , a lime feldspar, transparent and color¬ 
less, or translucent and grayish or reddish. 

Feldspars are essentially constituents of volcanic 
and crystalline igneous rocks, orthoclase being 
typical of granite, syenite, gneiss and trachyte, 
usually in association with quartz. 

Labradorite is the feldspar of basalts and doler- 
ites in microscopic crystals, and it also forms enor¬ 
mous rock-masses in Labrador. Oligoclase may be 
associated with orthoclase in granite, and is the 
feldspathic constituent of diorite and diabase . An¬ 
desite is the feldspar of the trachytes of the Andes. 
Albite is chiefly found in crystalline schists and also 
in granite veins. Anorthite is best developed in 
the crystalline limestone blocks of Vesuvius, and 
also occurs in some basalts. 

Micas. This embraces a group of minerals 
whose most marked common feature is a highly 
laminated structure, and they admit of being split 
into leaves even thinner than paper. They are 
colorless to brown, green, reddish and black, and 
occur either in small scales disseminated through¬ 
out rocks—as in granite—or in large plates. The 
micas are silicates of alumina with either potash, 
magnesia or iron and some other ingredients. 

The most important species of mica are: 

Muscovite. This is the common mica which in 


6 prospector’s field-book and guide. 

the form of clear or slightly smoky colored plates is 
used in the doors of stoves and lanterns. In Russia 
it was used for the windows of houses and this gave 
the name to the mineral of Muscovy glass, whence 
the mineralogical name of muscovite. 

Muscovite is a potash mica usually occurring in 
rhombic or six-sided tabular crystals. In many 
rocks the crystals are but poorly developed or only 
represented by irregularly shaped scales; cleavage 
basal and very perfect; color, mostly silvery-white, 
seldom, but occasionally, dark brown or black. 
Before the blowpipe it whitens and fuses on thin 
edges to a gray or yellow glass. Muscovite is not 
decomposed by sulphuric or hydrochloric acid. 

Phlogopite, a magnesia mica of light brown, or 
copper-red, and sometimes white, color. It is com¬ 
mon in limestone or in serpentine rocks and in 
dolomites. 

Biotite. This includes most of the magnesia-iron 
mica. Color, black or dark green. Very thin 
laminae appear brown, greenish or red by trans¬ 
mitted light. Luster pearly, hardness 2.5 to 3, 
specific gravity 2.7 to 3.1. The basal cleavage is 
highly perfect and the laminae are flexible and 
elastic as in other members of the mica group. It 
is only slightly acted upon by hydrochloric acid, 
but is decomposed by sulphuric acid, leaving a 
residue of glistening scales of silica. Biotite is the 
second most important mica. 

Lepidomelane is an iron-potash mica. It occurs 
in small six-sided tabular crystals, or in aggrega- 


preparatory instruction. 


7 


tions of minute scales. Color, black ; luster adaman¬ 
tine or somewhat vitreous. Easily decomposed by 
hydrochloric acid, leaving a fine scaly residue of 
silica. 

Lepidolite or lithia mica resembles muscovite in 
crystalline form and many of its physical properties. 
Its color is white, yellowish or rose-red, the last 
being very prevalent. It fuses before the blow r pipe 
more readily than muscovite, and is decomposed by 
hydrochloric and sulphuric acids but not so readily 
as the magnesian micas. Lepidolite is most com¬ 
monly met with in metalliferous veins, especially 
those containing tin, and is nearly alw T ays associated 
with other minerals which contain fluorine, such as 
fluorspar, topaz, tourmaline, and the emerald ; it is 
also frequent in many kinds of granite. 

Amphibole, often called Hornblende. The 
most common kind is an iron-bearing variety, in 
black cleavable grains or oblong black prisms cleav¬ 
ing longitudinally in two directions inclined to one 
another 124° 30'. It occurs also in distant prisms 
of this angle, and of all colors from black to green 
and white. 

Actinolite is the name applied to the green variety, 
and besides lime and magnesia, contains also iron. 
It occurs often in fibrous or columnar masses, some¬ 
times with a radiated structure. 

Tremolite is a lime-magnesia hornblende. The 
pure crystals are white, but the impure ones are 
yellowish or greenish-gray owing to the presence of 
protoxide of iron. There are several varieties of 
tremolite. Thus the substance known as 


8 prospector’s field-book and guide. 

Asbestus * is in most cases tremolite containing a 
little water. It generally occurs in fine fibers which 
may be isolated or packed closely together with 
their principal axes parallel. 

Mountain leather is a similar mineral, but the 
fibers are finer, closer and intermixed. 

Mountain cork is a spongy, elastic asbestus, with 
the fibers interlaced together. 

Mountain wood is like the last, but denser, far less 
elastic and capable of taking a high polish. 

Nephrite or oriental jade is a compact variety 
much used by t'he Chinese as a figure stone. The 
color is sometimes light-green as in the white jade ; 
and olive-green, as in the green jade. It has an 
uneven, fine-grained fracture, and a greasy luster. 

Tremolite is found in many places, but nearly 
always in the older dolomites and saccharoidal 
limestones. 

Pyroxene, including augite. Like hornblende 
in most of its characters, its varieties of colors and 
its chemical composition. But the crystals, instead 
of being prisms of 124° 30', are prisms of 87° 5'. 
Black and dark-green pyroxene in short crystals is 
called augite. It is an iron-bearing kind, and is 
common in igneous rocks. 

The minerals of the amphibole group closely re¬ 
semble pyroxene in chemical composition, while 
they also crystallize in the same system. They 

* Most of the asbestus mined for use in the arts is a fibrous 
variety of serpentine, and is easily distinguished because it contains 
about 14 per cent, of water. 


PREPARATORY INSTRUCTION. 


9 


differ, however, in the angular measurements of the 
oblique rhombic prism, which, as already shown, 
in hornblende is 124° 30', and in augite 87° 5' to 
92° 55'. 

They are all bisilicates of protoxides and sesqui- 
oxides, the former being lime, magnesia, soda, 
potash, and the protoxides of iron and manganese, 
while the latter are represented by alumina and the 
sesquioxides of iron and manganese. 

Crystals of amphibole differ from those of pyrox¬ 
ene, not merely in the angular measurements of 
their oblique rhombic prisms, but also in the 
angles at which their cleavage planes intersect. 
This circumstance is of considerable value to the 
mineralogist, since it is often difficult or impossible 
to measure the angles of the actual crystallographic 
faces, but it is generally possible to measure the 
angles of cleavage. The crystals of minerals be¬ 
longing to the amphibole group usually exhibit a 
fine longitudinal striation. 

Color affords no safe means of discriminating 
between pyroxene and amphibole, since the mem¬ 
bers of both groups exhibit greenish and brownish 
tints. The augites and hornblendes which occur 
in basalt are mostly brownish in color. 

The hornblende in syenite is also generally 
brown, but that which occurs in phonolite is mostly 
of a greenish tint, while the augite in leucite lavas 
is, as a rule, also green. 

The minerals of the amphobile group frequently 
show a tendency to develop long, blade-like crystals. 


10 prospector’s field-book and guide. 

This tendency is in a very marked degree shown by 
actinolite, one of the principal varieties of amphi- 
bole, the crystals arranging themselves in radiate 
groups. 

Both hornblende and augite occur together in the 
same rock ; but as a rule the former mineral is 
found in those rocks which contain a large percent¬ 
age of silica, the associated minerals being usually 
quartz and orthoclase. while augite is generally 
found in rocks of a basic character containing tri¬ 
clinic feldspars, and with little or no free silica. 

Chlorite occurs sometimes in thin, foliated 
plates like mica, but inelastic, more often granular, 
massive; sometimes in green crystals and scales. 
These kinds of chlorite are found in rocks, and form 
the mass of chlorite rock and chlorite slate. 

The chlorites are silicates of alumina, iron and 
magnesia with water, the average percentage of 
magnesia being about 34, and that of water over 12. 

Chlorite is a very soft mineral, and is essentially 
a product of the decomposition of other minerals. 

When heated in a glass tube it gives off water. 
Before the blowpipe it exfoliates, whitens and melts 
with difficulty into a grayish enamel. It is soluble 
in hydrochloric acid when powdered, and after long 
boiling. 

Talc. A hydrated silicate of magnesia from 
which the water is only driven off at a high tem¬ 
perature. It generally occurs in broad pale-green, 
or silvery-whitish plates or leaves, looking like 
mica, but the cleaved plates, though flexible, are 


PREPARATORY INSTRUCTION. 


11 


much softer and not elastic. It is easily scratched 
by the nail, has a pearly luster and is soapy and 
unctuous to the touch. Before the blowpipe it 
turns white and exfoliates. It is neither before or 
after ignition soluble in either hydrochloric or sul¬ 
phuric acid, thus differing from chlorite. 

Serpentine. This is also a hydrated silicate of 
magnesia. It is usually compact, massive, not 
granular at all, of a dark green color, but varying 
from pale green to greenish-black. The most pecu¬ 
liar variety is a fibrous kind occurring in seams in 
massive serpentine, which is called crysotile, popu¬ 
larly called asbestus. 

Minerals are composed of chemical elements, 
which are substances which cannot be further sepa¬ 
rated. A table of the chemical elements, their sym¬ 
bols, equivalents and specific gravities, is given in 
the Appendix. When these elements unite to¬ 
gether and form a compound, they always do so in 
fixed proportion and in definite weight. Therefore, 
in any pure mineral, whose composition is known, 
the amounts of the elements going to make up any 
given mass of it can be calculated by a rule-of-three 
sum. 

For example, in galena (PbS) we have lead (Pb) 
= 207 and sulphur (S) — 32, total 239. Therefore, 
in 239 lbs. of pure galena we will find 207 lbs. of 
lead (86^ per cent.), and so on in proportion. 

Thus any mineral that is pure enough to be 
weighed directly, or which can be concentrated pure 
and then weighed, can be estimated in this way, 
and the percentage content of the ore calculated. 


12 prospector’s field-book and guide. 

The combination of two or more of these elements 
together gives rise to three classes of substances, 
namely, acids , bases, and salts. 

Oxides of non-metallic elements are acids. 

Oxides of metallic elements are bases. 

Where an acid and a base unite, one exactly 
neutralizing the other, a substance is produced hav¬ 
ing neither acid nor basic tendency. It is known 
as a salt. 

Most minerals are salts. There is only one com¬ 
mon acid mineral, namely, quartz (Si0 2 ), or the 
oxide of the non-metallic element silicon. 

There are many minerals which are basic, such as 
hematite (Fe 2 0 3 ) and magnetite (Fe 3 0 4 ), the oxides 
of iron, and cuprite (CuO), the oxide of copper. 

Among the many minerals which are salts are: 
common salt or sodium chloride (NaCl); limestone 
or calcite (CaC0 3 ), formed from the union of the 
oxide of calcium (metal) and carbonic acid gas; 
gypsum (CaS0 4 2H 2 0) formed by the union of the 
oxide of calcium (metal) and sulphuric acid ; apa¬ 
tite, a phosphate of lime [Ca 3 (P 2 0 4 ) 2 ] formed by 
the same base as above, uniting with phosphoric 
acid. 

There are a great many minerals, the acid mem¬ 
ber of which is silica, with one or more metallic 
oxides forming the basic member. These are 
known as silicates , and feldspar, mica, hornblende, 
pyroxene, talc, serpentine, etc., are examples. 

These facts are important to remember, because 
whole families of minerals and rocks are classified 


PREPARATORY INSTRUCTION. 


13 


as acid or basic, according to the greater or lesser 
quantity of silica present in them. 

The colors of minerals are either essential to 
them, as in the sulphides, oxides and acidiferous 
compounds of most metals, and in those species of 
which they are essential constituents; or they are 
the effect of casual intermixture of these substances 
in species which, when pure, are naturally colorless. 
Of the latter sort are the colors of feldspar, calcspar, 
rock salt, marble, and jasper, in which the various 
tints of red and yellow are generally due to the 
oxide and hydrous oxide of iron. Other minerals 
derive a brilliant green color, some from carbonate 
of copper, others from the oxide of nickel or of 
chrome. In species of which the color is a perma¬ 
nent character, its intensity is often so far varied by 
a difference of texture or confused crystallization, 
that red, brown, and green substances appear, in a 
mass, to be black ; but on being pulverized, their 
true color will be seen. It is therefore advisable, 
in describing a mineral, to state what its color is 
when reduced to powder. 

The intermixtures of coloring matter, which are 
merely mechanical, render a mineral more or less 
opaque; thus the red and yellow jasper are chalce¬ 
dony—which when pure is highly translucent, or 
even semi-transparent—colored by minute particles 
of oxide of iron, which are themselves opaque. But 
colors, which, though they may not be essential to 
a species, are the result of chemical combination , do 
not impair its transparency ; such is the violet tint 


14 prospector’s field-book and guide. 

of amethyst, which is derived from a minute por¬ 
tion of the oxide of manganese combined with the 
quartz ; and the green of the emerald, which may in 
some cases be due to oxide of chrome. 

In consequence of the variable quantity of color¬ 
ing matter, whether chemically combined or other¬ 
wise, many substances present various tints and 
shades of color, so that they are particularized as 
blood-red, flesh-red, chestnut-brown, lemon-yellow, 
sky-blue, etc. 

Accidental colors being unequally distributed, 
often produce parallel bands, either straight or 
curved, and clouded forms, as in agates. Some¬ 
times the color takes the form of leaves and moss, 
or runs through the mass in veins, as in marble. 

There are still other colors, which are neither 
essential to minerals, nor yet produced by intermix¬ 
ture. Some, as the sulphide of antimony, exhibit 
a brilliant superficial tarnish, in which the pris¬ 
matic colors are regularly arranged. In transpar¬ 
ent substances, prismatic colors’are perceived in the 
interior, and arise from minute cracks or fissures 
containing films or particles of air ; these are often 
movable by slight pressure. 

A very curious peculiarity of color called poly- 
chroism is connected with the phenomenon of 
double refraction. Some minerals, placed between 
the eye and the light, transmit different colors in 
different directions. Tourmalines, viewed parallel 
to their axis, are generally opaque ; perpendicularly 
to it, they appear to be green, red, brown, etc. 


PREPARATORY INSTRUCTION. 15 

This difference is not observable in all double- 
refracting substances ; but in some which have two 
axes of double-refraction three different tints have 
been observed. Minerals crystallizing in the cubic 
system never transmit more than one color, if their 
composition and texture be homogeneous through¬ 
out. 

In some minerals a peculiar light is produced 
either by friction or heating them, which is called 
phosphorescence. On rubbing together two frag¬ 
ments or pebbles of quartz, a faint greenish light 
will be perceived, and the same effect can be pro¬ 
duced with certain marbles. Other substances 
when placed on a heated shovel, emit a brilliant 
phosphorescence, which in some is green ; in others 
pale violet. The best mode of conducting this 
experiment, if the specimen is powdered, or in 
small fragments, is to strew it over a shovel heated 
nearly to redness ; but if it be an inch or two in 
length, it is better to heat it slowly, and not beyond 
the necessary degree, by which means the operation 
may be frequently repeated without injuring the 
specimen. 

Some metals are found native and in some degree 
of purity, as in the cases of gold, silver, copper, 
mercury, and platinum, and when so found are 
readily determined at once by any one who is at all 
acquainted with those metals as they occur in gen¬ 
eral use. But frequently native metals appear 
under such colors, and even forms, that the dis¬ 
coverer must possess more knowledge than any one 


16 prospector’s field-book and guide. 

usually possesses who has seen the metal in the arts 
only. Gold, as an illustration, is frequently found 
in various shades of yellow, in accordance with the 
amount of silver or copper it may contain, and yet 
to the practiced eye of a true mineralogist it never 
loses the true gold hue. 

Iron pyrites, which is composed of sulphur and 
iron, and called “ pyrite,” mineralogically, has a 
color somewhat similar to that of gold, and so also 
has a mineral called “ chalcopyrite,” or copper 
pyrites, which contains copper, iron and sulphur. 
These, with others, vary in the yellow shade and 
degrees of color, but by the practiced eye are in¬ 
stantly detected. Of course the brittleness of these 
minerals is unlike the softness of native gold, and 
this would instantly reveal the fact that they were 
not gold ; but we are now speaking of the practiced 
eye alone, and therefore of the benefit of cultivating 
a knowledge by sight of minerals. The mode in 
which a mineral breaks when smartly struck with 
a hammer, or pressed with the point of a knife, is a 
character of importance. Many minerals can only 
be broken in certain directions, for instance, a 
crystal of calcspar can only be split parallel to the 
faces of a rhombohedron ; many crystals break more 
readily in one direction than in others. Whenever 
a mineral breaks with a smooth, flat, even surface, 
it is said to exhibit 

Cleavage, which always depends upon the crys¬ 
talline form. But minerals often break in irregular 
directions, having no connection whatever with the 
crystalline form, and this kind of breaking is called 


PREPARATORY INSTRUCTION. 


17 


Fracture. The nature of the surface given by 
fracture is often a character of importance, especially 
in distinguishing the varieties of a mineral species. 
Thus quartz and many mineral species show a 
shell-like fracture-surface which is called conchoidal, 
or if less distinct, small conchoidal or sub-conchoidal. 
More commonly the fracture is simply said to be 
uneven, when the surface is rough and irregular. 
Occasionally it is hackly, like a piece of fractured 
iron. Earthy and splintery are other terms some¬ 
times used and readily understood. 

Streak. The color and appearance of the line of 
furrow on the surface of a mineral, when scratched 
or rubbed, is called the streak, which is best ob¬ 
tained by means of a hard-tempered knife or a file. 
The color of a mineral and its streak may corre¬ 
spond, or the mineral and its streak may possess 
different colors, or the mineral may be colored while 
its streak is colorless. For instance, cinnabar has 
both a red color and a red streak ; specular iron has 
a black color, but a red streak ; sapphire has a blue 
color, but a white, colorless streak. The streak of 
most minerals is dull and pulverulent, but a few 
exhibit a shining streak like that formed on scratch¬ 
ing a piece of lead or copper. This kind of streak 
is distinguished by the name of metallic. In judg¬ 
ing the streak of a mineral, much-weathered pieces 
should be rejected. 

Hardness is another character of great import¬ 
ance in distinguishing minerals ; it is the quality of 
resisting abrasion. The diamond is the hardest sub- 
2 


18 prospector’s field-book and guide. 


stance known, as it will scratch all others. Talc is 
one of the softest minerals. Other minerals possess 
intermediate degrees of hardness. To express how 
hard any mineral is, it becomes necessary to com¬ 
pare it with some known standard. Ten standards 
of different degrees have been chosen, and are given 
in order in the following scale : 

1. Talc, easily scratched by the finger-nail. 

2. Gypsum , does not easily yield to the finger¬ 
nail, nor will it scratch a copper coin. 

3. Calcite, scratches a copper coin, but is also 
scratched by a copper coin. 

4. Fluorite , is not scratched by a copper coin, and 
does not scratch glass. 

5. Apatite , scratches glass with difficulty; is 
readily scratched by a knife. 

6. Feldspar , scratches glass with ease ; is difficult 
to scratch by a knife, but is scratched by a well- 
tempered steel. 

7. Quartz, cannot be scratched by a knife, and 
readily scratches glass. 

8. Topaz, \ harder than flint or quartz. 

9. Corundum., ) 

10. Diamond, scratches any substance. 

In describing minerals, their hardness is always 
expressed by numbers. Thus, if on drawing a 
knife across a mineral it is impressed as easily as 
calcite its hardness is said to be H3. If a mineral 
scratches quartz, but is itself scratched by topaz its 
hardness is between 7 and 8. 

In testing the hardness of a mineral a sound por- 


PREPARATORY INSTRUCTION. 


19 


tion of it should be chosen, and the scratch should 
be made on a smooth clear surface and with a 
sharp edge or angle of the mineral used for scratch¬ 
ing. A streak of dust on scratching one mineral 
with another may come from the waste of either, 
and it cannot be determined w T hich is the softer 
until after wiping off the dust, when it will be easily 
seen that no scratch has been produced on the 
harder mineral, and that the edge of the other has 
been blunted. This is what would happen if an 
attempt were made to scratch topaz with quartz, or 
corundum with topaz. 

By the test of hardness, clear distinctions may be 
drawn between minerals which resemble each other. 
Iron pyrites and copper pyrites, for instance, are 
similar in appearance, but copper pyrites can easily 
be scratched with a knife, while iron pyrites is 
nearly as hard as quartz and the knife makes no 
impression upon it. 

Flexibility and elasticity. Some minerals 
can be readily bent without breaking, for instance, 
talc, mica, chlorite, molybdenite, native silver, etc. 
Minerals which after being bent can resume their 
former shape like a steel spring, are called elastic* 
for instance, mica and elaterite. A remarkable in¬ 
stance of flexibility, even combined with elasticity, 
amongst the rocks, is that of a micaceous sandstone 
called itacolumite, which in Brazil is the matrix of 
the diamond. 

Smell. A few minerals only, like bitumen, have 
a strong smell which is readily recognized, but 


20 prospector’s field-book and guide. 

specimens generally require to be struck with a 
hammer, rubbed, or breathed upon before any smell 
can be observed. Some black limestones have a 
bituminous odor, while some have a. sulphurous, 
and others a fetid, smell. Hydraulic limestone 
has a smell of clay which can be detected when the 
mineral is breathed on. Some minerals containing 
much arsenic, for instance mispickel, smell Qf garlic 
when struck with a hammer. 

Taste. Only soluble minerals have any taste, and 
this can only be described by comparison with well- 
known substances, for instance acid, vitriol; pungent, 
sal ammoniac; salt , rock salt; cooling , nitrite ; astrin¬ 
gent, alum ; metallic astringent, sulphate of copper; 
bitter, sulphate of magnesia ; sweet, borax. 

Malleability. Malleable substances can be 
hammered out without breaking, and it is on this 
quality that the value of certain metals in the arts 
depends, for instance, copper, silver, gold, iron, etc. 

A few minerals are malleable, and at the same 
time sectile, i. e., they can be cut with a knife, for 
instance, silver glance, horn silver, and ozokerite. 

Mineral caoutchouc (elaterite) is sectile, but like 
india rubber, can only be shaped when hot. The 
elasticity of elaterite is so characteristic that the 
mineral will be readily recognized. 

Ductility, or the capability of being drawn into 
wire, is a property which is confined exclusively to 
certain metals. It is possessed in the highest degree 
by gold, which can be drawn into the finest wire, 
or rolled into leaves of such fineness that 30,000 of 
them are not thicker than an eighth of an inch. 


PREPARATORY INSTRUCTION. 


21 


Luster. The term luster is employed to describe 
with certain adjectives the brilliancy or gloss of 
any substance. In describing the luster, well-known 
substances are taken as the types, and such terms as 
adamantine luster —diamond-like—and vitreous luster 
—glassy—are used. The luster of a mineral is 
quite independent of its color. When minerals do 
not possess any luster at all they are described as 
“ dull.” The kinds of luster distinguished are as 
follows : 

Metallic: The luster of a metallic surface, as of 
steel, lead, tin, copper, gold, etc. 

Vitreous or glassy luster : That of a piece of broken 
glass. This is the luster of most quartz and of a 
large part of non-metallic minerals. 

Adamantine: This is the luster of the diamond. 
It is the brilliant, almost oily, luster shown by some 
very hard materials, as diamond, corundum, etc. 
When sub-metallic it is termed metallic adamantine, 
as seen in some varieties of white lead ore or 
cerussite. 

Resinous or waxy: The luster of a piece of rosin, 
as that of zinc blende, some varieties of opal, etc. 
Near this, but quite distinct, is the greasy luster , 
shown by some specimens of milky quartz. 

Pearly or the luster of mother-of-pearl. This is 
common where a mineral has very perfect cleavage. 
Examples: Talc, native magnesia, stilbite, etc. 

Silky, like silk. This is the result of fibrous 
structure, as the variety of calcite (or of gypsum) 
called satin spar, also of most asbestus. 


22 PROSPECTOR^ FIELD-BOOK AND GUIDE. 

Fusibility. Some minerals can be easily fused ; 
others only with difficulty ; while some resist the 
highest heat which can be applied to them. There 
are such wide differences between the‘various de¬ 
grees of fusibility of minerals that this character 
helps greatly in distinguishing them. The fusibility 
is most readily tested by holding a small splinter of 
the mineral with a forceps in a candle flame, urged 
by the blowpipe; or the mineral may be laid upon 
a piece of charcoal and the flame directed upon it 
by the blowpipe. Some minerals fly to pieces when 
heated ; others swell up or give off peculiar and 
characteristic odors. For further information re¬ 
garding fusibility, see Chapter II, The Blowpipe 
and its Uses. 

Specific Gravity. By specific gravity is meant 
the comparative weight of equal bulks. Water is 
taken as the standard of comparison ; the specific 
gravity of a mineral is a number showing how 
many times it is, bulk for bulk, heavier than water. 

Rule. The specific gravity of water is called 1, 
of gold ]9, implying that if equal bulks of gold and 
water were taken, the gold would weigh 19 tim'es as 
heavy as water. The specific gravity of a mineral 
can be found by weighing it first in the air in the 
usual manner, and then observing how much of its 
weight it loses when suspended from the arm or pan 
of a balance, and allowed to hang freely in water. 
If a piece of quartz weighing 26 grains is attached 
by a horse hair or fine silk thread to the scales— 
and weighed whilst hanging in water—it will be 


PREPARATORY INSTRUCTION. 


23 


found to weigh only 16 grains; it thus loses 10 
grains, or Jf of its entire weight. Similarly gold 
would lose iV of its weight. 

Minerals differ very widely in the proportion of 
weight which they lose in water, but the same min¬ 
eral invariably loses the same proportion, for in¬ 
stance : Quartz loses If- of its weight; topaz if; 
sapphire if ; zircon if ; tin ore if. 

These proportions depend upon the specific grav¬ 
ity of these minerals. The specific gravity of water 
is called 1, of quartz 2.6, of topaz 3.5, of sapphire 
4.0, of gold 19, signifying among other facts that 
quartz loses if of its weight in water, topaz if, sap- 
phire gold -A- 

In determining how much weight a mineral loses 
in water, a very delicate balance is required when 
the weight in air is under 10 grains; but for por¬ 
tions weighing heavier than this, a common balance 
turning readily to a grain, may be used for prac¬ 
tical purposes. The mineral must be sound 
throughout, and free from any pores or cracks, and 
its surface should be rubbed over with water before 
immersing it, to prevent bubbles of air adhering, 
which would falsify the result. A trial of specific 
gravity can have no value unless it is made on a 
pure portion of a mineral, quite free from any 
adhering foreign matter. 

The rule for finding the specific gravity is to 
divide the weight of the mineral in air by its loss 
of weight in water. Example : A piece of quartz 
weighed 1,398 grains in air and 862 grains in water ; 


24 prospector’s field-book and guide. 

hence the loss of weight is 536, and the weight in 
air divided by this number is 2.6, which is the 
specific gravity of quartz. Some rules for finding 
weights by specific gravity are given in the Appen¬ 
dix. 

However, while the specific gravity of a mineral 
can be ascertained with great accuracy in the lab¬ 
oratory where delicate balances are available, it is 
not always possible to do so in the field, and the 
most that can be undertaken is to class minerals 
roughly within certain broad limits. Prospectors 
soon acquire some proficiency in testing the weight 
of minerals by handling them. A lump of pyrite, 
for instance, can readily be distinguished from gold 
by its weight, since a mass of gold of the same size 
would weigh at least three times as much, and a 
little practice with well-known substances will 
enable the prospector to class most minerals within 
certain broad limits by weighing them in the hand. 

A rough idea of the specific gravity of minerals 
can be arrived at by washing in a tin dish. This 
process in the hands of an experienced prospector 
will give sufficiently accurate results for the de¬ 
termination of the most common minerals. The 
sorting in a tin dish is effected by picking out the 
larger stones by hand, but in testing the specific 
gravity of minerals, they should be divided, in the 
first instance, into regular sizes by sifting. For 
this purpose two sieves will be sufficient, one with 
eight holes, the other with sixteen holes to the 
linear inch; then all which will pass through the 


PREPARATORY INSTRUCTION. 


25 


coarser sieve, but not through the finer, will be of 
sufficiently uniform size for the tests required. 

The lighter portions will first be separated by 
washing ; these v will consist of shale, ferruginous 
quartz, brown oxide of iron, pebbles of tourmaline, 
etc., mostly of a lower specific gravity than 3.5, 
and the heavier minerals which remain in the 
dish, will be zinc blende, magnetite, pyrites, hem¬ 
atite, mispickel, tinstone, wolfram, gold, plat¬ 
inum, etc. 

By a careful manipulation of the dish generally 
adopted by miners when showing the gold, these 
heavy minerals can be easily enough separated into 
three groups, namely : Gold, platinum, copper, bis¬ 
muth, silver, mercury, etc.; tinstone, wolfram, 
galena, cinnabar, etc.; and zinc blende, magnetite, 
haematite, mispickel, etc. 

Some of these minerals, mispickel for instance, 
can be readily recognized, and where this is the 
case, those which lie upstream and those below can 
be subdivided as being of greater or less specific 
gravity respectively than 6.3, which is the specific 
gravity of mispickel. Where the minerals in the 
dish cannot be readily recognized, a few fragments 
of metallic antimony, or zinc, or tinstone painted 
white—all of which have a specific gravity of about 
7—should be introduced into the dish to serve as a 
gauge. 

What has previously been said of color may also 
be said of weight and form. A lump of pyrite in 
the hands of a skilled mineralogist would be dis- 


26 • prospector’s field-book and guide. 

tinguished from gold by its weight, since as above 
mentioned, a mass of gold of the same size would 
weigh at least three times as much. Three crystal¬ 
line pieces, the one of barite, the other two of lime 
carbonate and of quartz, may to the unskillful eye 
appear equally transparent; but the form of the 
first is tabular, that of the latter two is in six-sided 
crystals, but the lime carbonate crystals terminate 
in three sides, while the quartz always (like the 
sides) in six. 

Besides a knowledge of the forms under which the 
minerals we seek present themselves, it is also neces¬ 
sary to learn the characteristics of some of the rocks 
which are generally associated with those minerals. 
The object of this knowledge is to serve in directing 
us to those regions where we may with greater prob¬ 
ability discover the minerals we seek. It also serves 
to warn us out of a region where we should not 
expect to find what we desire. 

To illustrate, we may not expect to find iron ores 
of a certain kind, brown hematites for instance, in a 
granitic country. On the other hand, we may find 
the magnetic ores in such a region, and it is useless 
to explore a granitic region for black band iron ore, 
although it may be the proper region to discover 
red hematite. 

It is, therefore, important that the prospector 
should be able to distinguish many of the geologic 
rocks to help in guiding or in checking him, in his 
explorations. 

A general knowledge, therefore, of the manner in 


PREPARATORY INSTRUCTION. 


27 


which the geologic rocks are “ laid down,” their 
order, or succession, in the earth, is important, and 
the distinction between sedimentary and that which 
has been, and is usually called “ igneous rock,” but 
more properly “ azoic rock,” that is, rock which 
does not exhibit any remains of fossil or organic 
life. For often the only signs by which we can, 
with any degree of certainty, determine what is the 
name of the sedimentary rock is by finding the re¬ 
mains of former life, that is, the kind of fossil it 


Fig. l. 



Section showing contorted strata due to lateral pressure : aa, “ an¬ 
ticlinal axis; c, the “synclinal axis.” The direction of the arrows, ee, ee, 
is that of “the strike.” That of the arrows, dd, is that of “ the dip ” of the 
strata, always measured from the horizon ; gg, are the out-crops. 

contains. Prof. Dana says (The Amer. Journal of 
Science, Nov. and Dec., 1890) that it is settled that 
the kind of rock in itself considered is not a safe 
criterion of geological age. 

If all the rocks in the world had been laid down 









28 prospector’s field-book and guide. 

in regularly horizontal sequence and had always re¬ 
mained in their own separate “ horizons,” as every 
rock of the same age is called, not only should we 
find them all parallel, one over the other, but we 
might readily determine to some extent what were 
the exact order and distance of any one horizon, or 
geological age. But, although there is a general 
order, the same in all parts of the world, there have 
been upheavals and sinkings, dislocations and ero¬ 
sions, during the ages, so that it is necessary that 
the prospector should become acquainted with the 
various changes probable in the order and forms of 
the vast rocks which carry the minerals for which 
he is seeking. 

Some of these movements of the earth’s crust are 
represented in Fig. 1. 

PRACTICAL GEOLOGY. 

It may be repeated that it is of considerable im¬ 
portance that the prospector should have at least 
some general knowledge of those geological horizons 
with which his work is specially associated. As 
has been intimated, useful minerals do not always 
confine themselves to one horizon ; but there are 
certain ranges of rock which indicate their vicinity. 
There are also limits which are never overpassed 
by some useful minerals, and experience has shown 
that some horizons are always sterile in ores, and it 
is therefore useless ever to expect to find them in 
paying quantities, in certain rocks or beyond them 
in certain directions. 


PREPARATORY INSTRUCTION. 


29 


Gold often occurs where it will not pay to open 
and work the strata, so also with lead and copper. 
It is well to learn the relations of such barren 
regions, or horizons, as the strata are called. 

In the following table chief place has been given 
to these horizons which have been found in our 
own country to abound in the useful minerals, and 
we advise the possession of small specimens of the 
principal rocks mentioned and the special examina¬ 
tion of the specimens under a good lens, so as to 
become thoroughly acquainted with their appear¬ 
ance and their minute constituents. 

All rocks may be classed as— 

1. Igneous. 

2. Metamorphic. 

3. Aqueous. 

A rock may be defined as a mineral aggregate 
possessing a more or less persistent geological char¬ 
acter. However, speaking geologically, not only 
the hard consolidated massive and stony substances 
are called “ rocks,” but any natural deposits of 
stony material such as sand, earth, or clay, when 
in natural beds, are geological rocks. Very few of 
the rocks of this earth, at any rate so far as exam¬ 
ined, are in their original and primal condition. 
Even the granites and volcanic rocks are composed 
of other and more ancient material disintegrated, 
ground up, or worn down, settled, buried, and com¬ 
pressed by ages of enormous pressure, or consolidated 
by cementation. Some have been “ laid down ” 
under water, having been disintegrated into dust, 


30 prospector’s field-book and guide. 

carried by the winds of ages out over the oceans 
and seas, and settled down into the form of the 
present rocks, which afterward have been lifted up 
into mountains and plains above the seas. But by 
the transporting power of rivers or currents in 
ancient oceans, and because of unequal upheaval of 
some regions where subterranean forces were greater 
than at distant places, very large differences in the 
nature of the deposit have occurred, even in limited 
regions. These special and limited forces will ac¬ 
count for the fact that although, taking the geo¬ 
logical horizons throughout the world, there is a 
general sameness, differences do occur, and im¬ 
portant members of the order of succession are 
omitted in some regions, and exceptions to general 
rules occur. 

In the table following are therefore given those 
universally accepted relations of certain rocks, one 
to another, in the great geologic arrangement of the 
world, omitting some of the subsidiary, limited and 
unimportant horizons. 

1. IGNEOUS ROCKS are such as owe their origin 
to the action of fire, having been subjected 
to sufficient heat to melt the ingredients. 
They form the smaller, but still a very 
large, part of the crust of the earth. They 
are not sedimentary, but are due to up¬ 
heaval. They are not stratified and not 
fossiliferous. Some geologists divide them 
into plutonic and volcanic rocks, the former 
being crystalline, older, deeper in origin; 


PREPARATORY INSTRUCTION. 


31 


and the latter non-crystalline, and compara¬ 
tively recent and superficial. In the case of 
the plutonic rocks the rate of cooling has 
been slow, and the consolidation gradual, 
and has taken place under great pressure. 
The rate of cooling of the volcanic rocks 
has on the other hand been fast, and the 
consolidation rapid, as with lava, etc. 

Trachyte : A grayish rock of rough fracture ; the 
same specific gravity as quartz, but mainly 
constituted of grains of glassy feldspar. It 
is essentially a unisilicate of alumina, with 
10 to 15 per cent, potash, a little soda and 
lime; differs from quartz in that it fuses be¬ 
fore the blowpipe, while quartz remains un¬ 
fused except when soda is used. 

Basalt: Blackish or dark brown. Traps , green¬ 
stone, dolerite, amygdolite; these latter four are 
only modifications, being all unisilicates with 
• smaller amounts of potash than h\ trachyte, 
a little more soda and lime, and some traces 
of iron and magnesia, varying in color and 
form. 

Obsidian is a volcanic glass, something like 
bottle glass, of a dark shade, and translucent. 

All these are compact in texture except where 
some holes have been worn in by steam or gases. 
They are frequently found penetrating several strata, 
having been forced up in columns almost vertically, 
and sometimes spreading out horizontally for many 
miles between the strata or on the surface, and are 
called volcanic dykes, or intrusive rocks or lava. 


32 prospector’s field-book and guide. 

It is not certain that granite rocks are of igneous 
origin, but they seem to belong to the metamorphic 
series. 

2. METAMORPHIC ROCKS. The term meta¬ 
morphic as applied to these rocks, implies 
that they are the product of the metamor¬ 
phosis of rocks original^ sedimentary. They 
are of igneous origin, subsequently to the 
time when they were of aqueous origin, and 
have undergone a change through pressure 
and heat, and, perhaps in connection with 
steam and water. All the rocks of this 
class are to be distinguished from the igneous 
by their foliated texture and yet more by 
their alternate bedding in parallel layers or 
strata, and the traces which they often very 
distinctly show of internal stratification. All 
the metamorphic rocks are silicates and acid 
silicates. They contain from 42 to 75 per 
cent, of silica, and they all contain alumin¬ 
ium, magnesium, iron, calcium, in the above 
quantitative order, and all but talc schist 
contain small quantities of potassium and 
sodium. Of this class of rocks are the fol¬ 
lowing : 

Gneiss, having a composition of small pieces of 
feldspar, mica, and quartz, like some gran¬ 
ites, but laminated or foliated in form, and 
not equally solid, homogeneous, and contin¬ 
uous throughout its structure as granite is. 

Mica Schist. This term is given to those 


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•oja ‘opnaopoo ‘uoSaao ‘uojSupqsnM ‘npuaojipno up ospn :adoany ux pun ‘punpsi 8,jaAnoounA ‘punp 
-naz Matf ‘undnf ‘oSnpadxqoay unppui ‘nppui up anooo ‘popaay srqj jo (ajpuSpp jo imojq) sppapp pnoo 

‘NIX pun 998 ‘xunxpxji) 

WUNIXV'Id ospn inpAnppn pun ypjp aqj up aX09 -ajaqAvaspa pun ‘nuqoano qxnog ‘npuopy ux aan 
sn qons sjpsodap axupp jo ajnqdsoqd ‘puns ‘xunsd^S ‘sAnpo jaqjo pun jpopjq ppapi ‘sjpooj iijnpjjax 

qouxjxa 

ppn spnxupun ‘njnjjs aupjnxu 
pun japnAv qsajj supnjuoo 

•saxoads joupjxa 
jo quao jad 08 supnjuoo 

•sppaqs jo saxoads Supjsp 
-xa jo quao ja<i OS jnoqy 

aNaooa 

•aNaooiK 

aNaoonx 

TERTIARY OR 
CENOZOIC. 


sapoads Supjspxa jo ajn 
sauoq pun sppaqs sjp ppy 

•AHVNaaxvnfr *o 
‘aNaooxsiaqj 
‘xNaoaa 


‘S0IXSIH3X9VHYH0 

•SNOisiAiaans 

•SNOisiAia avaaNao 



‘S 300 H aaijiixvaxs 

















































































































































« 
































• 

































































i . 

.1 









































PREPARATORY INSTRUCTION. 


33 


laminated rocks composed of mica and quartz 
in small particles, easily broken up, but more 
easily broken into tabular or leaf-like pieces, 
because the mica has been deposited in 
planes allowing of cleavage. 

3. THE AQUEOUS ROCKS are simple water 
rocks—that is, rocks composed of sediments 
from the dust or ground-up remains of other 
rocks. The presence of such sediments is 
due to the transporting power of rivers, 
floods, or currents, and also of winds and 
storms and other agencies, carrying the dust 
to the ocean waters where it was arrested 
and became a sediment. 

These rocks are, as a rule, stratified, or made up 
of successively deposited strata. They are almost 
in all cases fossiliferous. 


Fig. 2. 



Sandstone. 


In sandstone (Fig. 2), the grains of sand are 
rounded, having no sharp edges as in granite. 
Where the sedimentary material was exceedingly 
3 


















34 PROSPECTORS FIELD-BOOK AND GUIDE. 

dust-like, it sometimes is laid down as fine mud and 
frequently in laminae, as in shale (Fig. 3). 

Granite is a term descriptive of rocks generally 
composed of quartz, feldspar and mica, in grains 
(hence the name) of a crystalline form. But the 
granites are not all alike in the amount of either of 
the above-mentioned minerals, nor are they alike in 
color. Some granites contain no mica, as in graphic 


Fig. 3. 



Shale. 


granite, only quartz and feldspar, and the quartz in 
the feldspar resembling written characters. Others 
contain hornblende as well as mica, or in the place 
of mica; the hornblende being in dark or black 
crystalline specks, pieces, or crystals, and consisting 
essentially of silica, magnesia, lime, and iron. 
This granite is called syenite granite. Where the 
feldspar is in distinct crystals in compact base, and 
sometimes lighter than the base, which is frequently 
reddish, purple, or dark green, it is a porphyritic 
granite. The granites are sometimes whitish, gray¬ 
ish, or flesh-red. They are considered as meta- 
rnorphic and not igneous (Dana), although some 


PREPARATORY INSTRUCTION. 


35 


authors still consider them to be igneous. They 
always present a crystalline grain in varying de¬ 
grees of fineness and prominence. One form is 
given in Fig. 4, from a specimen in the author’s 
possession. 

This specimen contains two kinds of mica, one 
black, biotite, the other white of silvery appearance, 


Fig. 4. 



Granite with black mica and feldspar crystals, with quartz as chief base. 


muscovite. The biotite presents in spots the appear¬ 
ance of hornblende, and only the pen-knife point 
shows the scaly lamination of mica under the lens. 
It also contains crystalline forms of potash feldspar 
(, orthoclase ), distinguishable from the quartz by their 
sides only, by the lamellar fracture of its edges, and 
its peculiar vitreous glimmer, for practically the 
hardness appears the same, although feldspar is (6.6 
and quartz 7) slightly softer. It would be well for 
the prospector to gather many forms of granite and 
examine them under the lens until he becomes 
thoroughly used to the variations. 

The rocks have since their formation been sub¬ 
jected to numerous changes. Some have "been 
raised from thejsea without being lifted to any ex- 


36 prospector's field-book and guide. 

tent from their original horizontal position; others 
have been folded into most fantastic shapes; and 
others again have been completely inverted. In 
other cases, movements which have taken place 
since the rocks became solidified have caused frac¬ 
tures, and by the rocks on one side of the crack slid¬ 
ing on those of the other, faults have been produced. 

Where the rocks have been folded in the form of 
an arch, they are said to form an anticlinal , and 
where they occupy a basin, they are spoken of as 
forming a synclinal. 

In examining the surface of a country in which 
the rocks are of sedimentary origin, it will be found, 
as a rule, that the beds are inclined at varying 
angles to the horizon, and in making a geological 
survey of any special district it is necessary to note 
the strike of the rocks at every available point. 
When any well-marked bed occurs, its line of out¬ 
crop should be carefully followed and mapped ; the 
boundaries of any eruptive rocks should also be 
clearly delineated on the plan. 

The strike of a rock is the direction of a horizontal 
line in any of the beds, or, in other words, the direc¬ 
tion in which a level drive would be put in on the 
floor of the bed. The dip is a line at right angles 
to the strike on the plane of the beds, and the angle 
is to be measured in relation to the horizon. 

When any particular bed is followed on the sur¬ 
face, it is often found that it does not continue with 
the same strike for any great distance ; that, in fact, 
it gradually veers round, the direction of the dip 


PREPARATORY INSTRUCTION. 


37 


changing at the same time. The boundaries of 
rocks are sometimes rather obscure in consequence 
of the variable movements which have taken place, 
but the tracing of them on the surface is made most 
difficult by the occurrence of faults and dykes. The 
displacement due to faults may be only an inch or 
so, or may be several hundred feet, while in excep¬ 
tional cases it may be as much as two or even three 
miles. 

A study of faults is of great importance, more 
especially on account of their close association with 
mineral lodes. 

The first indications of a deposit possessing 
economic value are, as a rule, to be met with among 
the materials forming the beds of streams, and 
wherever water-courses have seamed and furrowed 
the rocks. Metalliferous deposits should be looked 
for in hilly districts as a general rule, though 
alluvial accumulations may be found in compara¬ 
tively flat country. A close study of natural phe¬ 
nomena will often help in the discovery of mineral 
wealth. Thus the form and color of the surface; 
stained patches; springs of water whether sweet or 
mineralized; scum floating on water (petroleum, 
etc.); accumulations of earth brought to the surface 
by burrowing animals ; changes in vegetation ; be¬ 
havior of the magnetic needle. These, however, 
only.serve to indicate existence without reference to 
quantity or quality. 

The valuable minerals and metal-bearing deposits 
of the earth occur as 


38 prospector’s field-book and guide. 


Lodes. By a lode or vein is generally meant a 


Fig. 5. 



FORMATION, CROSS-SECTION. 


I, I, I, I, country rock enclosed in lode on horse , surrounded by auriferous 
quartz. A, A, hanging wall; B, B, foot wall; C, C, casing; D, D, D, D, 
country rock. 


fissure in the rocky crust of the earth which is filled 





PREPARATORY INSTRUCTION. 


39 


with mineral matter. In Australia a vein is called 
a reef and in California a ledge. The course of a 
lode in a horizontal direction is called its strike , 
while its descent is spoken of as its dip. Very often 
lodes are distinctly marked off from the rocks en¬ 
closing them by straight and sharp divisions on 
either side of the lode as if cut with a knife. 
These divisions are called the walls of the lode. 
When the lode inclines in its dip to either one side 
or the other, which is nearly always the case, the 
upper division is called the hanging-wall , and the 
lower the foot-wall. The incline of the load in its 
dip is its underlie. The barren rock through which 
the lode passes is known amongst mining men as 
the “country.” Lodes may be all widths from a 
thin thread-like film to 100 feet or more in width. 
Lodes often contain large blocks of the country 
rock barren of ores or metals, which are therefore 
waste. Such occurrences are spoken of as forma¬ 
tions or horse , and are generally of great width 
between the two walls. See Fig. 5. 

Lodes nearly always carry casing , which is coun¬ 
try rock ground very fine, converted into clay by 
moisture and mixed with quartz and free native 
gold. The casing mostly occurs on the foot-wall, 
and is often very rich in metal. Fig. 6. 

When an outcrop of mineral has been found and 
the strike, in case of a lode, has been determined, it 
is advisable to test it along the surface at various 
points to prove its continuity and comparative rich¬ 
ness at different points. It must not be assumed 


40 prospector’s field-book and guide. 

because a lode is rich where found that it will be 
equally so at all points where it is intersected ; and 
equally, because a lode is poor where first discov¬ 
ered, there is no reason to suppose that further 
prospecting along its course may not disclose parts 
in which valuable minerals occur. 

When surface prospecting has given as much in- 


Fjg. 6. 



Showing solid quartz lode, with casing. Tranverse section. 

1,1, solid quartz lode without horse; 2, 2, casing of soft dig; 3, hanging- 
wall ; 4, foot-wall; 5, 5, country rock. 


formation as possible, some sinking and driving 
should be undertaken to prove the continuity and 
value of the deposit in depth. To acquire the great¬ 
est amount of information at the minimum cost, the 
point for sinking a shaft should be selected on the 
surface where the ledge is at its best and, having 


PREPARATORY INSTRUCTION. 


41 


determined the extent along the strike, as nearly as 
possible, which carries payable mineral, the shaft 
should be placed about the center and sunk on the 
underlay to a depth of 100 feet, or less, if the water 
level is reached sooner ; and from the bottom levels 
should be driven along the course of the lode as 
long as the mineral is of sufficient value to pay. 

It will be seen that by these means a plot of 
ground can be cheaply opened, in which a certain 
quantity of ore can be measured and sampled, and 
an accurate idea of its value obtained. In measur¬ 
ing up quartz it is usual to estimate 13 cubic feet to 
the ton, in the solid, so that a vein 3 feet wide 
proved to a depth of 100 feet and for 100 feet along 

.. , „ . 100X100X3 

its line ot strike would contain--=2307 

tons. 

The stone should be sampled every few feet and 
taken from wall to wall in order to arrive at a fair 
estimate of its value. 

In following up other minerals than gold, it must 
be borne in mind that many of them have a ten¬ 
dency to decompose w T hen exposed to the action of 
the weather and, consequently, that the nature of 
the ore at the outcrop may be very different to what 
will be found in depth. Copper ores, for instance, 
are very liable to decompose and, forming sulphates 
which are soluble, to be carried away in solution by 
running water. As most copper ores are associated 
with a greater or less quantity of iron, the outcrop 
of copper lodes are very frequently represented by 



42 prospector’s field-book and guide. 

a porous ironstone which is called gossan, and no 
sign of copper is found until some depth has been 
sunk. Generally speaking an outcrop of porous 
gossan may be looked upon as a very good indica¬ 
tion for mineral in depth ; whereas, a dense iron¬ 
stone seldom leads to rich deposits of other mineral 
below. 

Beds and layers. The most common of bedded 
deposits are those of coal. Many kinds of iron ore 
are found in beds, also some copper ores in shale, 
silver and lead ore in sandstone, etc. Beds and 
layers are also known as strata, measures, sills, mines, 
bassets, delfs , girdles. 

Irregular deposits, such as pockets, etc., which lie 
sometimes in various formations. Contact deposits, 
net-work of veins, and where mineral is diffused 
through rocks, or in small cracks. 

Many of the irregular deposits are of great value 
and some of the rarer minerals, such, for instance, 
as sulphide of bismuth and native bismuth are 
found in them. These irregular deposits are not 
only irregular in their mode of occurrence but vary 
much both in size and shape so that no one by sur¬ 
face indications is able to form any opinion regard¬ 
ing their extent. It is even more important in 
testing these deposits when an outcrop has been 
found, than it is in the case of a ledge, to follow 
them carefully in the workings. Any drives or 
shafts which may be commenced should follow the 
direction of the ore after its extent has been proved 
as far as possible by these prospecting works. 


PREPARATORY INSTRUCTION. 


43 


Surface deposits. Ity surface deposits are under¬ 
stood the beds of alluvium which more or less cover 
the face of every country. These beds have been 
chiefly created by various mechanical agents, which, 
after having degraded the higher rocks, carry the 
material which has thus been formed down to lower 
levels. By this process of degradation most mineral 
deposits are so comminuted that by their exposure 
to the atmosphere they are decomposed and de¬ 
stroyed. However, substances like cassiterite, plat¬ 
inum, gold, etc., not being so readily subject to de¬ 
composition, have, in consequence, been more or 
less preserved and buried among these superficial 
deposits. In observing deposits of this kind notice 
has to be taken of their general situation, area, 
thickness and richness. Often several beds may be 
ranged one above- the other, in which case their 
relative values have to be determined. In tracing 
any particular deposit, as, for example, whilst 
ascending a valley, if the particles of ore increase 
in size and number, the prospector may expect 
that he is approaching their common origin. An¬ 
other indication that he is near this point of origin 
will be that he shall find the mineral less worn. 

Comprehensively speaking, all metals are found 
in the oldest rocks only, and the latter form the 
backbone, so to speak, of the main ranges of metal¬ 
liferous countries. Therefore, the prospector in 
making his road towards the mountains will have 
to select a spot for starting actual operations. For 
this purpose a locality should be chosen where the 


44 prospector’s eield-boor and guide. 

rocks are neither too hard or too soft, nor should 
they be of too uniform a character. The country 
most deeply indented with gullies, canons and 
gulches running parallel to one another offers the 
best chances of success. The region near the 
sources of the main rivers is generally the richest 
in metals and always the most easily prospected, re¬ 
quiring less labor and time in its examination, the 
loose debris and wash being of much less depth 
on account of the greater fall in the river and creek 
beds than at other portions of the courses. 

Auriferous lodes are most likely to be met with 
near the headwaters of river systems, and very fre¬ 
quently the alluvial gold begins at or near the 
locality where a number of auriferous lodes exist. 
This is a very common occurrence, and may be in 
the great majority of cases relied upon. 

When a river forks at its head into two or more 
branches, it is strange to say, the source of the gold 
will nearly always be found in the right-hand 
branch, geographically speaking. It may be men¬ 
tioned that in determining the right- and left-hand 
branches or banks of a river or stream, you are sup¬ 
posed to stand at the head of the river or stream 
looking towards its mouth or outlet. Amongst 
miners this is very often reversed, and quite a num¬ 
ber of branches are named left-hand which, properly 
speaking, ought to be right-hand branches. 

This right-hand theory is an old mining supersti¬ 
tion for which science has offered no explanation, 
but the almost unfailing applicability of the theory 


PREPARATORY INSTRUCTION. 


45 


is fully established by practical experience. Speak¬ 
ing of mining superstitions, it may be added that 
the spots upon which the sun shines before noon 
are held by miners to be richest in metal. Every 
old gold-miner will pin his faith to this theory. 
What makes these observed facts—for they really 
amount to that—all the more remarkable is, that 
they may be applied with an equal degree of liability 
to the Northern and to the Southern hemispheres, 
which makes these superstitions appear in a para¬ 
doxal light. However, they have survived the test 
of hundreds of years in Cornwall and on the Conti¬ 
nent of Europe, and have been confirmed by further 
observation in California and Australia. The latter 
instance, i. e., the spots upon which the sun shines 
before noon, may find an explanation in the fact 
that landslides and elevations of rock of all kinds 
are of more frequent occurrence upon the sunny 
than upon the shady side of valleys, the greater 
amount of disintegration of the rocks leading to a 
greater accumulation of the metals. However this 
may be, the theory forms one of the golden rules of 
the prospector. 

The color of the rocks also serves as a guide to the 
prospector. Rocks of a pinkish-reddish color alter¬ 
nating with rocks of a deep bluish tint streaked 
with drab are generally very favorable to metallic 
deposits. Another good indication is when the 
faces of the precipices are covered with a black 
ooze caused by manganese, the presence of which 
always indicates a mineralized district. These are 
simply general indications. 


46 prospector’s field-book and guide. 

Although color is always a good guide to the 
location of metallic deposits, it is of special service 
to the prospector in unexplored districts. Thus 
copper is indicated by greenish, bluish or reddish 
stains upon the rocks in the neighborhood of the 
lode; tin and manganese by dull, black tints; 
manganese shows itself also in pinkish streaks. 
Gold, being always accompanied by iron, mani¬ 
fests its presence in red, yellow or brown shades; 
lead and silver reveal grey or bluish-grey tinges; 
blende dyes the rocks yellowish-brown, and iron 
disports itself in all the hues of red, yellow-brown, 
and even dun-black. 

The wash of rivers and creeks , and even more so 
that deposited upon terraces (if any) flanking the 
streams, must claim the close attention of the pros¬ 
pector. By wash is meant the diluvial drift in 
which gold or tin—the only metals mined in 
diluvial deposits—is found. The colors in connec¬ 
tion with the different metals mentioned above 
apply also to stones and the wash generally, though 
in a modified degree. Stones streaked with pinkish 
lines, and lines indicating manganese, are always 
found in wash conveying gold. Green stones, which 
are universally found in the wash, are always a 
good indication of gold if they are of a bright sea- 
green or even pea-green, but they must be smooth, 
hard, well-polished and very heavy. In many dis¬ 
tricts such stones^are considered the ‘‘pilot stones ” 
to gold. Quartz stones must be always present in 
goodly numbers in every gold-bearing wash, and if 


PREPARATORY INSTRUCTION. 47 

they are in a decaying state, they are all the better 
as a favorable indication. 

A very large portion of the gold which has come 
into the possession of men has been obtained from 
superficial deposits called placers. Deposits of 
placer gold are always found adjacent to and lying 
below districts traversed by auriferous veins, and 
nowhere else. The areas where the quartz veins 
occur have suffered great erosion, which has tended 
to break down and comminute the quartz, and to 
liberate and wash the contained gold. 

Placer gold is found mingled with rolled frag¬ 
ments of quartz and in the irregularities of the 
surface of the bed rock, where a washing process on 
a large scale has been active. 

The nuggets and coarsest gold are found nearest 
the outcrops of the quartz veins that have sup¬ 
plied them, while particles become gradually finer 
and finer as the line of drainage is followed from 
this point. 

Pebbles and fragments of gold-bearing quartz 
which have been derived from the neighboring 
veins are commonly found in the placer deposits, 
and most of the nuggets have more or less quartz, 
like that of the veins still adhering to them. The 
gold is found in scales, grains, pebble-like nodules 
and round, battered masses or nuggets. 

Such alluvial deposits demand very careful atten¬ 
tion. They are of the greater importance because 
alluvial gold and tin are in many cases found under 
conditions which require no capital to work them 


48 prospector’s field-book and guide. 

and, consequently, immediate returns can be ob¬ 
tained when discovery has been made. River beds 
and creeks should be carefully examined, a pick 
and a shovel, a tin dish and a large knife being all 
the equipment necessary. In the first place the 
gravels of the stream should be washed carefully 
with the object of determining whether any gold at 
all exists. Next certain beaches along the course 
of the stream should be selected and shallow pits 
sunk through them until bed-rock is met with, and 
all the material raised should be panned, bearing in 
mind that the best gold is generally found on the 
bed-rock. 

A further test should be made by carefully fol¬ 
lowing up the stream, especially when it is low, and 
cleaning out with a knife all crevices in the rocks in 
which gravel and sand have accumulated, and this 
should all be panned. In some cases large quanti¬ 
ties of gold have in a short time been saved by 
prospecting in this manner. 

However, the gold which is found in rivers and 
streams does not necessarily point to the close prox¬ 
imity of the ledges from which it was derived ; still 
less does the occurrence of alluvial gold in buried 
river beds indicate the proximity of ledges. A care¬ 
ful prospector will often notice that a river or stream 
which he is testing appears at certain points to have 
altered its course, having, in fact, found it easier to 
cut a channel in a different direction to that which 
it originally followed, it has done so leaving its 
former channel, with the gravels and sands it had 
deposited, high and dry. 


PREPARATORY INSTRUCTION. 


49 


In cases such as this, it is generally worth while 
to sink prospecting shafts through the gravel until 
bed-rock is reached and, if the first is not successful, 
others should be sunk towards the upper part of the 
channel as defined by the inclination of the bed¬ 
rock where it is met with. There are, of course, 
comparatively few prizes and many blanks in pros¬ 
pecting such as this, but the value of the deposits 
found at times offers inducements to prospectors to 
continue trying, even when but small success has 
attended their earlier efforts. 

The domain of the prospector lies in hilly ground. 
Flat plains have little attraction for him except 
under special conditions, because, though valuable 
minerals may be present, they are certain to be 
covered by an enormous deposit of soil. 

In character, placer diggings manifest almost as 
great variety as vein deposits. The following illus¬ 
trations show in section some forms of these alluvial 
deposits: 

Fig. 7. 


The stream (Fig. 7) flows across the strike of the 
rocks, and the gold is found below a hard bar; a, 
4 





50 prospector’s field-book and guide. 

surface of stream; b, mud and gravel forming bed 
of stream; c, bed-rock; d, auriferous gravel re¬ 
tained by the projection of the bed-rock. 

In Fig. 8 the stream flows as in Fig. 7, across 
the strike of the rocks, but the gold is found on one 
side of the creek, a, bank of stream ; b, mud and 


Fig. 8. 



other worthless matter lying on the pay dirt; c, 
auriferous gravel accumulated in the deepest parts 
of the stream. 

In Figs. 9 and 10, a represents the stream ; b, 
mud and gravel at bottom of stream; c, bed-rock; 
d, pot-holes in bed-rock where auriferous material 
has lodged. 

In Figs. 9 and 10 the stream generally runs 
with the strike of the rocks, or at a slight angle ; 


Fig. 9. 



but the dip is nearly perpendicular in those in¬ 
stances where pot-holes have been known to occur. 






PREPARATORY INSTRUCTION. 


51 


In estimating the value of alluvial claims it is of 
the utmost importance to consider the cheapness 
and abundance of the water supply and, what is of 
no less importance, the facilities afforded by the 
surrounding levels for the disposal of the debris of 
the mining operations or waste material, called 


Fig. 10. 



tailings , from which the gold has been excavated or 
removed, so that the gold-bearing layer may be 
reached. 

Beach placers. On the Pacific shores of America, 
extending in patches for a considerable distance, as 
far up as Alaska, are a number of auriferous de¬ 
posits known as beach placers. They appear to be 
surface concentrations due to wave action, and an 
enrichment of this type seems to take place after 
heavy storms. Under such conditions the waves 
cut back into the coastal-plain sediments and concen¬ 
trate the heavy material as a surface layer. The 
occurrence of these deposits is of interest, because 
they indicate that certain regions are auriferous. 
The richest deposits of this character are the famous 
beach placers at Nome, Alaska, 




52 prospector’s field-book and guide. 

Indicative Plants. From very early times it 
has been noticed that the soil overlying mineral 
veins is favored by special vegetation, and though 
the occurrence of such vegetation cannot be taken 
as an infallible indication of the existence of such 
veins, it will be interesting to record the results of 
past observations, so that they may serve for a 
guidance to further observation in future. 

Indication of lead. The lead plant ( Amorpha 
canescens) is said by prospectors in Michigan, Wis¬ 
consin and Illinois to be most abundant in soils 
overlying the irregular deposits of galena in lime¬ 
stones. It is a shrub one to three feet high, cov¬ 
ered with a hoary down. The light blue flowers 
are borne on long spikes, and the leaves are ar¬ 
ranged in close pairs on stems, being almost devoid 
of foot-stalks. 

Gum trees, or trees with dead tops, as also sumac 
and sassafras, are observed in Missouri to be abund¬ 
ant where “ float ” galena is found in the clays. 

Indication of iron. A vein of iron ore near Siegen, 
Germany, can be traced for nearly two miles by 
birch trees growing on the outcrop, while the re¬ 
mainder of the country is covered with oak and 
beech. 

Indication of limestone. The beech tree is almost 
invariably prevalent on limestone, and detached 
groups of beech trees have led to discoveries of 
unsuspected beds of limestone. 

Indication of 'phosphate. The phosphate miners 
in Estremadura, Spain, find that the Convolvulus 


PREPARATORY INSTRUCTION. 


53 


alth&oides, a creeping plant with bell-shaped flowers, 
is a most reliable guide to the scattered and hidden 
deposits of phosphorite occurring along the contact 
of the Silurian shales and Devonian dolomite. 

Indication of silver. In Montana experienced 
miners look for silver wherever the Eriogonum ovali- 
folium flourishes. This plant grows in low, dense 
bushes, its small leaves coated with thick, white 
down, and its rose-colored flowers being borne in 
clusters on long, smooth stems. 

Indication of zinc. The “ zinc violet/’ Galmeiveil- 
chen or Kelmesblume (Viola calaminaria) of Rhenish 
Prussia and neighboring parts of Belgium, is there 
considered an almost infallible guide to calamine 
deposits, though in other districts it grows where no 
zinc ore has been found. In the zinc districts its 
flowers are colored yellow, and zinc has been ex¬ 
tracted from the plant. The same flower has been 
noticed at zinc mines in Utah. 

In looking for indications where superficial de¬ 
posits are known to occur, the prospector may be 
often guided, like the Tungusians in Northern Sibe¬ 
ria, who search for gold by first looking at the general 
contour of the country, and observing those places 
where any obstacles, like a projecting range of hills, 
would be likely to prevent material from being 
directly washed from higher to lower ground. 
Holes, sudden bends, or anything which would 
cause a diminution in the force of a current of 
water, are points at which it should be expected 
that heavy material like gold or platinum would be 


54 prospector’s field-book and guide. 

likely to collect. Although in Australia the most 
gold is generally found in pot-holes and behind 
hard bars, it has often been found upon the shallow 
bends of ancient river courses. The lowest of a 
series of beds is generally the richest. In California 
the gold-bearing beds usually consist of gravels, 
which may be cemented to form a conglomerate, 
sands, bands of tuff, clay, fossil-woods, etc. 

Magnetite occurs in alluvial deposits. Bog iron 
and manganese ore which have accumulated by 
precipitation in marshy places or in lakes, usually 
contain too much impurity to be of commercial 
value. Stream tin occurs in gravels in much the 
same way as gold. 

In examining a lode, the nature of the various 
minerals it contains and the proportions which 
these hold to each other should be observed. Some¬ 
times it will be noticed that certain groups of min¬ 
erals are often found together, the presence of one 
being favorable to the existence of the other. At 
other times the reverse will be remarked, the exist¬ 
ence of one mineral being the sign of the absence of 
another. The practical advantages to be derived 
from a series of observations indicating such results 
are too obvious to be overlooked. 

The following table, showing the association of 
ore in metalliferous veins, is given by Phillips and 
Yon Cotta: 


PREPARATORY INSTRUCTION. 


55 


Two Members. 


Galena, blende. 


Iron pyrites, chal- 
copyrites. 


Gold, quartz. 


Cobalt and nickel 
ores. 


Three Members. 


Galena, blende, iron 
pyrites (silver ores). 


{ 


Iron pyrites, chalcopy- j 
rites, quartz (copper ■{ 
ores). 


Gold, quartz, 
rites. 


iron py- 


Magnetite,chlorite, j 


Four or More Members. 

[ Galena, blende, iron py¬ 
rites, quartz and spathic 
J iron, diallogite, brown 
spar, calc spar or heavy 
( spar. 

r Iron pyrites, chalcopyrite, 
j galena, blende; and 
spathic iron, diallogite, 
brown spar, calc spar; 
l or heavy spar. 
r Gold, quartz, iron pyrites, 
galena, blende; and 
j spathic iron, diallogite, 

| brown spar, calc spar; 
l or heavy spar, 
f Cobalt and nickel ores, 
iron pyrites ; and galena, 
blende, quartz, spathic 
iron ore,diallogite,brown 
spar, calc spar ; or heavy 
spar. 

Tin ore, wolfram, quartz, 
mica, tourmaline, topaz, 
etc. 

Gold, tellurium, tetrahe- r Gold, tellurium, tetrahe- 
drite(various tellurium < drite, quartz; and brown 
ores). ^ spar ; or calc spar. 

C Cinnabar, tellurium, tetra- 
Cinnabar, tetrahedrite, j hedrite, pyrites, quartz; 

pyrites (various ores of J and spathic iron, diallo- 
quicksilver). I gite, brown spar, calc 

( spar ; or heavy spar. 

/ Magnetite, chlorite, gar- 
Magnetite, chlorite, gar- J ne ^ pyroxene, horn- 

net - v blende, pyrites, etc. 


Cobalt and nickel 
and iron pyrites. 


ores, 


l 


Tin, ore, wolfram.Tin, ore, wolfram,quartz 

Gold, tellurium. 


Cinnabar, tetrahe¬ 
drite. 



CHAPTER II. 


THE BLOW-PIPE AND ITS USES. 

All chemical tests for minerals, whether with 
the blow-pipe or in the wet way, depend upon some 
chemical change which is brought about, thus 
allowing the element, base or acid, to be recognized. 
These changes consist either of the decomposition of 
the mineral or the formation of fresh compounds. 
The following instances will sufficiently illustrate 
the character of these changes. 

If the oxide of a metal, copper for instance, is 
mixed with carbonate of soda and fused on char¬ 
coal, the copper is reduced to a metallic state, the 
oxygen combining w 7 ith the charcoal to form car¬ 
bonic acid, which escapes as a gas, and any silica 
which is present decomposes the carbonate of soda 
to form a silicate of soda, which may be looked 
upon as a slag. 

If a hydrous mineral is heated in a glass tube 
closed at one end, the water is given off, and con¬ 
denses as drops in the cool part of the tube. 

If an arsenical mineral is heated in a closed tube 
a crystalline deposit of arsenic is formed in the 
tube; but if it is heated in the air, white fumes of 
arsenious acid are evolved which smell like garlic. 
(56) 


THE BLOW-PIPE AND ITS USES. 57 

If a drop of hydrochloric acid be placed on a car¬ 
bonate, such as limestone, the presence of carbonic 
acid is recognized by the effervescence which takes 
place; the stronger acid having combined with the 
lime has liberated the carbonic acid in a gaseous 
form. In the case of very many mineral car¬ 
bonates, the acid requires to be heated for this re¬ 
action. 

A great deal can be learned respecting a mineral 
by a few simple trials with the blow-pipe, and every 
prospector should learn to use it. The chief re¬ 
quirements are a plain brass blow-pipe about 7 to 10 
inches long, a candle, a forceps or pliers, some 
platinum wire, a small pestle and mortar made of 
agate, a small sieve, a magnet, some small glass 
tubes, and some good firm charcoal free from cracks 
and openings. 

The only reagents which will be absolutely neces¬ 
sary are borax, carbonate of soda and, rarely, micro- 
cosmic salt, nitrate of cobalt, and a little hydro¬ 
chloric and sulphuric acid. A few others are 
occasionally necessary, but their use is limited. 
The carbonate of soda should be perfectly dry, not 
merely dry to the touch, but quite free from water. 
Such carbonate of soda may be prepared from com¬ 
mon washing soda by expelling the water it con¬ 
tains. Put the washing soda in a shallow, clean 
iron dish, and place it over a clear fire until a white, 
dry powder is formed ; avoid too strong a heat, 
otherwise the dry powder might fuse. A quarter of 
an ounce may be kept in a well-corked bottle or 


58 prospector’s field-book and guide. 

tube for use. Bicarbonate of soda may be used in¬ 
stead without previous heating, or if the bicarbonate 
be moderately heated it loses weight, and becomes 
carbonate of soda, quite free from water, like the 
above. 

The borax is to be dried in the same way; a 
quarter of an ounce will be enough. It is conve¬ 
nient to keep the platinum wire in the same tube. 
Unless these tubes are well corked, these chemicals 
reabsorb moisture. For testing tin ore it is useful 
to have a little cyanide of potassium kept in a bottle, 
with the cork and rim well covered with melted 
beeswax ; it would otherwise liquefy by absorption 
of moisture and become useless. It is a most dan¬ 
gerous poison, and the greatest caution must be 
observed in its use. 

The blow-pipe should have a fine jet, or aperture, 
wide enough to admit of a fine needle. The mode 
of using it may be readily acquired by first breath¬ 
ing through the nostrils with the lips closed, then 
puffing out the cheeks (as if rinsing the mouth with 
water), still keeping the lips closed, and breathing 
as before. The blow-pipe may at this point be 
slipped between the lips, and it will be found that a 
current of air escapes through it without any effort 
on the part of the operator. Air flows through the 
pipe owing to the tendency of the distended cheeks 
to collapse; it must never be forced from the lungs. 
After a little practice the strength of the current 
may be increased. By breathing entirely through 
the nostrils, keeping the lips closed, the blast may 


THE BLOW-PIPE AND ITS USES. 


59 


be kept up for ten minutes or longer without ex¬ 
haustion or inconvenience, except a slight fatigue 
of the lips in holding the blow-pipe. The beginner 
may practice blowing upon a piece of charcoal. 
The charcoal should, for convenience’s sake, be cut 
into slices of some six inches long by three-quarters 
to an inch wide and half an inch thick. Place a 
piece of lead, or a pin-head, or fragment of pyrite 
(iron pyrites), near the end of the charcoal, and learn 
to blow the flame of a candle to a point upon the 
object. However awkward the blow-pipe may feel 
at first, practice will soon enable the learner to be 
expert. At first it may be necessary to gouge a 
small hole or recess in the coal with the point of 
your pen-knife, in order to prevent the specimen 
from being blown away. But after many trials 
such a command will be had over the blast that the 
hole may be made sufficiently deep by simply turn¬ 
ing the point of the flame upon the coal and burn¬ 
ing out a cavity. 

Study the two colors of a sperm candle flame 
(Fig. 11). Notice that there is a yellow flame out¬ 
side and nearer the top, and then within the flame 
there may be seen a bluish, probably a true blue, 
flame. These flames act differently on the same 
substance. The outer, 0 F, or yellow flame, is 
called the “ oxidizing flame,” the inner, the “ reducing 
flame,” R F, or IF. By blowing properly, these 
two flames may be made to turn horizontally, or 
even downward, and then either the 0 flame or the 
R flame may be turned on the “ assay ” (as the ob- 


60 prospector's field-book and guide. 

ject on the charcoal may be called). Get a piece of 
iron ore as large as a pin-head and place it in a 
little cavity on the charcoal, then cover it with a 
quantity of soda carbonate as large as the assay. 
Now turn the R flame down on the soda and ore, 
and in a few seconds the ore will melt and be re¬ 
duced to metallic iron, and your magnetized knife- 


Fig. 11. 



A , the blue or reducing flame; B, the oxidizing flame; C, the end of the 
blow-pipe. 



By placing the end of the blow-pipe in the flame thus, the oxidizing flame 
B, is made more efficient. 

blade will pick it and the soda up. In this experi¬ 
ment a piece of red or brown hematite, or a piece of 
pyrite (iron pyrites), should be used, as neither will 
be attracted by the knife-blade before the ore is re¬ 
duced to metallic iron. The reason for this action 
on the part of the ore is that the ore is metallic iron 
combined with oxygen , and the R or blue flame calls 
for more oxygen than it possesses, so that when it is 











THE BLOW-PIPE AND ITS USES. 


61 


turned upon the hot oxide of iron it takes the 
oxygen it calls for from the ore and leaves the iron 
in a metallic state. But in the pyrite, which is iron 
and sulphur, the latter is partially driven off by 
either flame; and this process, on a larger scale, is 
called “roasting ” The soda absorbs a part of the 
sulphur and part remains in the iron, but not so 
much but that the magnetized knife-blade will at¬ 
tract it. The last experiment is good for experi¬ 
mental practice, but not for illustrating the two 
properties of the flame. 

The following is an excellent practical illus¬ 
tration in showing the characteristic power of either 


Fig. 12. 


A 

O 


L.L IJJOOLlJLJUn 



Appearance and size of wire and of loop, A. 


flame. Get some platinum wire of the size of a 
large horse-hair. Wrap it around a match, leaving 
an end extending an inch and a half beyond the 
match end, then roll the end of the wire around 
another match until you have bent the end of the 
wire into a small loop (Fig. 12). Prepare a little 
powder of common borax, and then, heating the 
wire loop in the general flame, plunge it quickly 
into the powdered borax. It will immediately pick 
up a quantity of the powder, and then, by turning 
the flame upon the borax, you will have a clear and 
perfectly transparent bead filling the little loop on 




62 prospector's field-book and guide. 

the end of the wire. You are now ready for the 
experiment of illustrating the special properties of 
the two flames, which will now be described. 

Obtain some black oxide of manganese from any 
druggist, and dropping a little upon a clean sheet 
of letter-paper, heat your borax bead red-hot in the 
flame and quickly touch with the hot bead a parti¬ 
cle of the black oxide—it will stick to the bead— 
then turn the outer or 0 flame upon the bead and 
blow till the particle of oxide of manganese has en¬ 
tirely dissolved—it will impart to the bead a beauti¬ 
ful amethystine-purple. Now turn the inner flame 
that is, the R flame, upon the bead, and in a few 
seconds (according to skill in keeping the R flame 
steadily on the bead) the color will disappear, but it 
will return when the 0 flame is used again. 

These efforts will give practice, ending in suffi¬ 
cient skill to enable the learner to use the blow-pipe 
as directed in the future parts of this w r ork. 

The various reactions of different substances are 
given in the body of this book as they are called for 
when the substances are described. 

A glass tube of a little less than three-eighths of 
an inch in diameter may be made into a blow-pipe 
as follows : Take a piece of such a tube, ten or twelve 
inches long, soften the tube by red heat in an alco¬ 
hol flame, and draw it out to a small diameter— 
cool and scratch or file it at the smallest diameter 
—break it off, introduce the tube into the flame 
again and bend the glass to a right angle, about 
two inches off from the point—cool gradually—and 


THE BLOW-PIPE AND ITS USES. 63 

heat the mouth end, opening it a little by introduc¬ 
ing a small, dry, pine stick, cool it, and you have a 
very efficient blow-pipe when another of metal can¬ 
not be had. 

Note: If your platinum loop will not hold the 
borax head, then it is too large. Make a smaller 
loop. If it is dimmed or blackened by smoke, heat 
it red-hot—it will clear up. 

The three principal means of chemically testing 
minerals before the blow-pipe are (1) with borax ; 
(2) on charcoal, usually with the addition of car¬ 
bonate of soda; (3) by holding in the oxidizing 
point. 

In connection with this the following experiments 
given by Alexander M. Thomson, D. Sc., are of in¬ 
terest : 

Experiment No. 1 .—Many metals impart a color 
to fused borax, by which their presence can be 
recognized. To try this experiment, a bead of 
fused borax must first be obtained on the platinum 
wire. The end of the wire is bent into a loop or 
ring about the twelfth part of an inch in diameter. 
The wire is then heated in the blow-pipe flame, and 
dipped whilst hot into the borax ; the portion of 
borax that adheres is then fused on to the wire in 
the blow-pipe flame, and the hot wire is again 
dipped ; this is repeated until the loop contains a 
glass-like bead of borax. If the bead has become 
cloudy, the soot causing this may be burnt off in 
the oxidizing point of the flame. Having thus ob¬ 
tained a clear, colorless, transparent bead, the next 


64 prospector’s field-book and guide. 

step is to add to it a minute portion of the mineral 
which is to be tested. By touching a little of the 
finely-pulverized mineral with the borax bead, while 
softened by heat, enough will adhere to the bead for 
a first trial. The bead is then kept at a white heat 
in the oxidizing point of the flame for a few seconds, 
and on removal its color is noted, both whilst hot 
and when cold. If no color is imparted, a fresh 
trial may be made with a larger quantity of the 
powder; but if >the bead is opaque owing to the 
depth of color, as is often the case, a fresh experi¬ 
ment must be made, using a still smaller quantity 
of the powder. The color can only fairly be judged 
in a perfectly transparent bead. If no color can be 
obtained in the oxidizing point, further experiment 
with the borax bead is needless; but if a color is 
obtained, it is then advisable to try the effect of the 
reducing flame upon the same bead. The following 
observations and inferences may result from this test: 


COLOR OF BEAD IN 

Oxidizing 

Green (hot); blue (cold) . 

Blue (hot and cold) . •. . 

Amethyst .... ... 

Green. 

Red or yellow (hot) . . . 

Yellow or colorless (cold) . 


Reducing Presence of 

• Red.Copper. 

• Blue. .Cobalt. 

. Colorless.Manganese. 

. Green.Chromium. 

| Bottle-green .... Iron. 

Violet (hot); red-brown (cold). Gray and turbid, diffi¬ 
cult to obtain . . ; Nickel. 


This mode of testing may often be used to prove 
the presence of the above-mentioned metals. 

It requires some practice before reliable results 










THE BLOW-PIPE AND ITS USES. 


65 


can be obtained in reducing. The reduced bead, if 
brought out of the flame at a white heat into the 
air, may at once oxidize ; but this may be prevented 
by placing it inside the dark inner cone of an ordi¬ 
nary candle flame, and allowing it to cool partially 
there. 

Experiment No. —The mode of testing with car¬ 
bonate of soda on charcoal is performed as follows: 
A sound piece of charcoal half an inch square is 
chosen, and a neat cavity is scooped out on its 
surface, in which is placed a mixture containing 
the pulverized mineral to be tested, with three or 
four parts of carbonate of soda, the whole not ex¬ 
ceeding the bulk of a pea. After lightly pressing 
the mixture into the cavity, the blow-pipe flame 
may be cautiously applied to it; and afterwards 
when the mixture no longer shows a tendency to 
fly off, the charcoal may be advanced nearer to the 
blow-pipe, and finally be kept at as high a tempera¬ 
ture as possible, in the reducing part of the flame. 

In testing for tin ore, a piece of cyanide of potas¬ 
sium, about the size of a pea, may be placed upon 
the mixture after the first application of heat, and 
the further application of heat may then be con¬ 
tinued. 

This treatment is designed to extract metals from 
minerals ; it favors in the highest degree the re¬ 
moval of oxygen. But, like the borax test, it is 
limited in its application, as it can only be used to 
detect certain metals. The failure of the test in any 
case must not be looked upon as a conclusive proof 
5 


66 prospector’s field-book and guide. 

of the absence of the particular metal sought; for 
instance, copper can be easily extracted from car¬ 
bonate of copper by this test, but not from copper 
pyrites. Still the test is a most valuable and indis¬ 
pensable one to the mineralogist. The test is com¬ 
plete when the metal is obtained as a globule, in 
the cavity of the charcoal. In many cases the 
globule will be found surrounded by the oxide of 
the metal, forming an incrustation on the charcoal; 
and the color of such incrustation should be care¬ 
fully noted, both at the moment of removal from the 
flame and after cooling. By pressing the globule 
between smooth and hard surfaces it can be deter¬ 
mined whether the metal is flattened out (or malle¬ 
able) or crushed to pieces (brittle). 

The following observations and inferences may 
result from this test: 


Incrustation Presence of 

None.Gold. 


Globule 

Yellow, malleable 
White, malleable 
Red, malleable . 

White, malleable 
White, malleable 
White, brittle. . 

None. 

White, brittle, giving 
off fumes when re¬ 
moved from flame White.Antimony. 


None. 

None. 

White. 

Red (hot); Yellow (cold) . 
Red (hot); Yellow (cold) . 
Yellow (hot); White (coldh 


Silver. 

Copper. 

Tin. 

Lead. 

Bismuth. 

Zinc. 


Experiment No. 3 .—In addition to these substances 
there are others which occur abundantly in minerals, 
and which may be recognized by the blow-pipe with 
the greatest ease; for instance, sulphur and arsenic. 









THE BLOW-PIPE AND ITS USES. 


67 


These may be discovered by heating a fragment of 
the mineral, supported on a piece of charcoal or 
held in a forceps in the oxidizing point of the flame, 
and comparing the odor which is given off. A 
smell of burning sulphur indicates that the mineral 
contains that substance, and white fumes having a 
garlic odor indicate the presence of arsenic. 

Mercury, antimony, and other substances may 
escape as fumes when heated in this manner. 

Nitrate of cobalt dissolved in water, and used in 
exceedingly small quantity, helps to discriminate 
between certain white minerals, such as kaolin, 
meerschaum, magnesite, dolomite, etc. The mineral 
is reduced to powder and moistened with a drop of 
a very light solution, and then heated before the 
oxidizing flame of the blow-pipe. Kaolin and other 
minerals containing alumina assume a rich blue 
color, while meershaum and other minerals con¬ 
taining magnesia become flesh-colored. Oxide of 
zinc, under the same circumstances, becomes green, 
and this can be tried with the white coating ob¬ 
tained on charcoal by reducing an ore of zinc with 
carbonate of soda. 

Tests in glass tubes can be better made over a 
spirit lamp, so as to avoid the deposit of soot on the 
glass, but they can also be made with the blow-pipe 
flame, provided it is used carefully, avoiding too 
sudden a heat, which would break or fuse the glass. 
The presence of water in minerals will be detected 
in this way, as the water collects in small drops in 
the cold part of the tube. Some minerals contain- 


68 prospector’s field-book and guide. 

ing sulphur, arsenic, antimony, tellurium and selen¬ 
ium often give a characteristic deposit. 

Minerals containing mercury can also be tested 
in this way, as by adding a little carbonate of soda, 
sometimes with cyanide of potassium, a sublimate 
of metallic mercury will be formed in the cold part 
of the tube. A little charcoal should be added to 
arsenical minerals. 

Organic combustible minerals generally leave a 
deposit of carbonaceous matter at the bottom of the 
tube, and the volatile hydrocarbons condense in the 
cooler part. The tube should, therefore, always be 
long enough to allow for this condensation. Min¬ 
erals which yield a characteristic smell will be best 
tested in this way. 



CHAPTER III. 


CRYSTALLOGRAPHY. 

The jorms which many minerals assume always 
indicate their composition. It is, therefore, some¬ 
times a great help to the prospector to become ac¬ 
quainted with the subject of crystallography so far 
as to enable him to determine the system or order 
to which a crystal belongs. 

We shall treat of the subject only so far as may 
be of practical application to the purposes of the 
prospector in the search for the useful minerals. 

It is necessary to understand that nearly all 
mineral substances, when they appear in the crys¬ 
talline condition, assume a characteristic form and 
do not trespass upon that of other minerals. Al¬ 
though, to the unaided eye and unskilled vision, 
this assertion may appear to be a mistake in some 
few cases, it appears so only because the differences 
are exceedingly small. 

All crystalline forms have been reduced to six 
classes or systems, which are named as follows: I. 
Isometric; II. Tetragonal; III. Hexagonal; IV. Or¬ 
thorhombic; V. Monoclinic; VI. Triclinic. 

I. Isometric system. The principal forms of this 
system are the cube, octahedron, dodecahedron, the 
( 69 ) 



70 prospector’s field-book and guide. 

two trisoctahedrons, the tetrahexahedron, and the 
h exoctahedron. 

The cube has six equal and square sides, as in 
Fig. 13. In this form lines drawn from the center 
of each face to the face opposite, cross each other at ' 
right angles , and are of the same length. 

This system is called isometric , that is, iso equal , 
and metric measure, because these axes or lines are 
of equal length and at right angles to each other. 

It must, however, be remembered that the cube is 
modified in some minerals, but wherever these 
modifications take place the original form of the 
cube may always be traced. Some of the changes 
may be very intricate, and these especially unusual 
or intricate forms we shall not notice. The usual 
forms only are of importance, and can be treated of 
in so small a work as this. 

The learner should take a potato and cut as per¬ 
fect a cube as possible, and make himself acquainted 
with the common variations which may belong to 
the cube, as we shall show, with¬ 
out changing the length of the 
axis, and cutting so that the 
axis will always be the same or 
of equal lengths. 

Fig. 13 is the cube with the 
three axes A A', B B f , C C'. If, 
with your knife, you slice off one 
edge angle from A to C and from A to C, and in 
like manner from A to B' and from A to B, you 
will have a four-sided pyramid, the apex of which 


Fig. 13. 


K an 



The Cube. 





CRYSTALLOGRAPHY. 


71 


will be at A and the four-sided base at C B', C B, 
or around one-half the cube. Now, treat the oppo¬ 
site side in the same way, and you will then have 
the following figure, which is the octahedron 
(Fig. 14). 

The dodecahedron (12 sides), Fig. 15, may be 
formed by taking off the solid angles A, B, B ', A'. 
In all three cases and in many others, the three axes 
remain the same in length, and in their angular 
direction where the forms have not been distorted. 



II. Tetragonal system. The chief forms of this 
system are the two square prisms and pyramids, 
and the eight-sided prism and double eight-sided 
pyramid. 

The tetragonal system has also three axes as in 
the isometric, and they are at right angles to each 
other, but the vertical axis is longer than the others, 
as in Fig. 1G. 

The term tetragonal means “ four-cornered or 
-angled,” and is not precise, for a cube is tetragonal, 
but it is used to express this form because it is one 
word; otherwise “ square prismatic ” would be a 





72 prospector’s field-book and guide. 

more correct description, since Fig. 16 is that of a 
prism ; for in mineralogy any crystal having par¬ 
allelograms for sides is called a prism. Cut this 
prism as in the case of the cube, and you will have 
the form seen in Fig. 17. 

Variations upon this form may show a prism with 
four-sided termination at either or both ends, as in 
Fig. 18. This is the form of the transparent gem 
called the zircon , anciently called the jacinth. The 
zircon has been mistaken for the diamond, which it 
resembles in brilliancy, and somewhat in hardness. 


Fig. 16. Fig. 17. Fig. 18. 



Tetragonal Prism. Tetragonal Octahedron. The Zircon. 


But the diamond is isometric and never tetragonal, 
and hence it may be distinguished readily from the 
zircon. 

III. Hexagonal system. The chief forms of this 
system are the two six-sided prisms, the two double 
six-sided pyramids, and the twelve-sided prism and 
double twelve-sided pyramid. It differs from the 
tetragonal system in that it has three equal lateral 
axes instead of two; the vertical being at right 
angles, as in Fig. 19, with each of the three lateral. 












CRYSTALLOGRAPHY. 


73 


But it must be remembered that owing to various 
causes in nature the hexagonal crystal always calls 
for hexagonal terminations; thus Figs. 20 and 21. 

Owing to various causes in nature, the hexagonal 
crystal may be found under various modifications 
of the hexagonal form, but it can always be reduced 
to this system. The symmetry of the crystals may 
be by sixes, or very rarely, by cutting each angle, 
it may be in twelves, or the sides may be unequal 
in area or length, as in Fig. 20. The author once 
found a quartz crystal in Switzerland which was, for 


Fig. 19. 





- 

H. 


r 

Tv 
; \ 



Hexagonal Prism. 


Fig. 20. 



Fig. 21. 



Quartz-Crystals—Hexagonal. 


nearly its entire length, three-sided, but showed its 
hexagonal nature only at the extremity, where, 
having been free from its confinement in process of 
formation, it had assumed its normal crystallization. 
As has been said in another place, calcite crystals 
sometimes assume a hexagonal prism precisely as 
does quartz, but the latter shows always six-sided 
terminations, whereas lime or calcite crystals show 
three-sided terminations, as in Figs. 22 and 23. 
There are two sections or forms of this system, the 
hexagonal and the rombohedral; both belonging to 
















74 prospector's field-book and guide. 


the hexagonal system, and distinguished as we have 
shown. 

These calcite crystals belong to the rhombohedral 
section of the hexagonal system, showing rhombo¬ 
hedral forms at the end, as in Fig. 17. 


Fig. 22. Fig. 23. 



Calcite hexagonal crystal—three-sided The same—end view, 

termination. Side view. 


IV. Orthorhombic system. The characteristic 
forms of this system are the rhombic prism and 
pyramid. There are also other forms called domes. 



In this system the three axes are unequal and in¬ 
tersect at right angles, as in Fig. 24, wherein the 
axes, A, B, C, are unequal in length, but at right 


















CRYSTALLOGRAPHY. 


75 


angles at the intersection. The terminations are 
flat, although frequently beveled on the surrounding 
edges. 

V. Monoclinic system. The monoclinic forms 
are too difficult to be fully described here, but it is 
not hard to learn what is most essential about them. 
In this system two of the axial intersections are at 
right angles; but one is oblique, and the side of 
the crystal is inclined, as in Fig. 25. 

Crystals of feldspar in general which contain pot¬ 
ash (called orthoclase or potash feldspar), are mono- 
clinic, but the soda feldspar crystals belong to the 
next or sixth system, as do also the lime feldspars. 

VI. Triclinic or “ thrice inclined” system. In 
this system the planes are referred to three unequal 
axes all oblique to each other. The only import¬ 
ant feature in this system is that there is no right 
angle in any of its crystals ; but it is of little use for 
our purposes, since with the exception of the lime 
feldspar and soda-lime feldspars (anorthite or lime 
feldspar, labradorite or soda-lime feldspar, andesite 
and oligoclase, both soda-lime feldspars, and albite, 
a soda feldspar) all the rest are of little importance, 
except microcline, a potash feldspar. 

As ILLUSTRATIONS OF THESE SYSTEMS the follow¬ 
ing may be stated : 

Of the isometric system, or first system, are gold, 
silver, platinum, amalgam, copper, the diamond, 
garnet, magnetite, pyrite, galena, alum, kalinite, all 
of which assume the cubic octahedral, or more allied 
form. 


76 prospector’s field-book and guide. 

Of the tetragonal, or second system, are the zir¬ 
con, chalcopyrite, cassiterite (tin ore), titanic oxide, 
and others. 

Of the hexagonal, or third system, are beryl, 
aquamarine, the emerald, chrysoberyl, apatite (lime- 
phosphate), quartz. 

Of the orthorhombic, or fourth system, are 
barite or sulphate of barytes, celestite or sulphate 
of strontia, and carbonate of strontia, also cerussite 
or lead carbonate. 

Of the monoclinic, or fifth system, are borax, 
gypsum, glauber salt (mirabilite is its mineralogical 
name), copperas (or melanterite). 

Of the sixth system we have already given suffi¬ 
cient illustrations. 

Of the gems not mentioned in the above, the tur- 
quois owes its blue to copper, and is never crystal¬ 
lized, being in reniform or stalactitic conditions. It 
is a phosphate of alumina with water in composi¬ 
tion. This mineral or gem should be carefully 
distinguished from lazulite, which, though blue, 
crystallizes in the monoclinic, or fifth system ; it is a 
softer mineral, and contains considerable magnesia, 
lime and iron, of which (except a very small 
amount of iron) the true turquois contains none. 
The latter is the gem, and may be beautifully pol¬ 
ished, and keeps its color, which is due to copper. 
Lazulite is found in beautiful crystals at Crowder’s 
Mount, in Lincoln Co., N. C.; also fifty miles north 
of Augusta, at Graves’s Mount, in Lincoln Co., 
Georgia. 


CHAPTER IV. 


SURVEYING. 

There are a few simple measurements which are 
sometimes desirable, and which can be made with¬ 
out the labor of carrying instruments and chains. 
The actual work of surveying, to be of any value to 
the prospector, must be so accurately performed that 
the work should be entered upon as a specialty, and 
he must use a theodolite or transit and make use 
of logarithms. Any small work on surveying or 
trigonometry will give sufficient information.* 

Some few measurements, however, and simple 
surveys with easy methods, are given here to meet 
cases where only a general approximation is re¬ 
quired. 

TO MEASURE HEIGHTS WHICH ARE INACCESSIBLE. 

Any height of tower, stand-pipe, tree, etc., may 
be measured approximately by knowing your own 
height and taking advantage of sunlight, thus : 


* For this purpose we would recommend the following book : The 
Practical Surveyor’s Guide. By Andrew Duncan. A new, revised 
and greatly enlarged edition. Illustrated by 72 engravings. Phila¬ 
delphia, Henry Carev Baird & Co., 1905. Price, $1.50, 

( 77 ) 


78 prospector's field-book and guide. 

Let A B, Fig. 26, be the height of the object to 
be measured. The dotted line is the shadow cast. 
Walk off into the sunlight and note on the ground 
the point at which your own shadow terminates; 
measure from the heel to that point. A calculation 
in single “ rule of three ” will give A B thus : 

a B' : B f A' :: B C : A B. 

Heights of hills or land may be nearly enough 
measured by the aneroid barometer, the instructions 
in the use of which go with the instrument, or may 
be obtained with it, and approximately accurate 


Fig. 26. 



aneroids may be had small enough to go into the 
side pocket, or still more accurate ones may be 
easily carried in a case held by a small strap around 
the shoulders. For hills under 2,000 feet, the fol¬ 
lowing rule will give a very close approximation, 
and is easily remembered, because 55°, the assumed 
temperature, agrees with 55°, the significant figures 
in the 55,000 factor, while the fractional correction 
contains two fours. 

Observe the altitudes and also the temperatures 




SURVEYING. 


79 


on the Fahrenheit thermometer, at top and bottom 
respectively of the hill, and take the mean between 
them. Let B represent the mean altitude and b the 

B—b 

mean temperature. Then 5500 X-= height 

B+b 

of the hill in feet for the temperature of 55°. Add 
T 4 0 - of this result for every degree the mean temper¬ 
ature exceeds 55° ; or subtract as much for every 
degree below 55°. 

TO MEASURE AREAS. 

Theoretically, it is very easy to “ step off lines,” 
but practically it is very difficult thus to arrive at 
accuracy on uneven land. But where one is ac¬ 
quainted with the exact average measurement of 
his step on level land, he ma}’ reach some approxi¬ 
mate accuracy on uneven land hy remembering 
that in ascending, even slightly, his average de¬ 
creases, and vice versa in descending. A good strong 
tape-measure, kept on a level in ascending and de¬ 
scending hills, is more convenient and more easily 
handled than a chain. 

L On square areas the length of the side multi¬ 
plied into that of the adjacent side gives the area. 

2. In the parallelogram, where all angles are 
right angles, the same is true. 

3. In any other shape the following rules are to 
be observed : 

First: Measure the area of a right-angled tri¬ 
angle thus: 



80 prospector’s field-book and guide. 


Fig. 27. 


Let B, Fig. 27, be the right angle; the area of 
A B C is equal to the length, 
B C , multiplied into half 
the perpendicular distance, 
A B. 

Example: B (7=100 ft.; 
therefore, if A B = 90 ft., 
100 X 45 = 4500 sq. ft. = 
area of A B C. 

The same rule applies 
when the triangle is not a 



right-angled triangle; thus, the angle at A, Fig. 28, 
being obtuse. 

D (7=150 ft., A B =90 ft.; multiply 150 ft. by 


Fig. 28 . 


A 



C 


one-half A B = 45 ft., and we have 6750 sq. ft., for 
A C D is composed of two right-angled triangles, 
A C B and A B D, as in the previous example. 

Or, when the triangle has an acute angle at A, 
Fig. 29, thus: Treat precisely as in Fig. 28, only 
letting the perpendicular fall from D upon A C, 
that is, invert the triangle. 

The cases wherein the sides are more than three 







SURVEYING. 


81 


are treated by resolving all such areas into right- 
angled triangles, thus: 

In Fig. 30 the area, A C D B, may be resolved 
into two triangles, A C B and C D B, of which A B 


Fig. 29. 





is the base of the one and C B that of the other. 
In Fig. 31, the area, A C D B E K> may be re¬ 
solved into the four triangles, AC D, AD B, ABE 
and A E K. The perpendiculars of Fig. 30 are 


Fig. 30. 
C 



E D and C F. Those of Fig. 31 are C H, I B, 
F E and K G, and the length of bases may be 
multiplied into half that of the perpendiculars, as 
in the case already given, and the feet be reduced 
to acres, rods, etc., or miles. 

6 




82 prospector’s field-book and guide. 


For the number of square feet in an acre, etc., 
see Appendix No. 3, and treat it thus: Suppose the 
area of Fig. 31 he 80,000 sq. ft., then according to 

Fig. 31. 


C 



Table No. 3, it will be 1 acre, 3 roods, 13 poles, 25 
yards, 7 feet, or 1.836 + acre. 

to measure an inaccessible line. 

Suppose we desire to measure the distance across 
a river, as in Fig. 32. 

We want to find the distance A B. Measure a 
distance of about 100 ft., B D, at right angles to 
,A B, and raise a pole at C, about half-way from B 
to D. Proceed in measuring at right angles to B D, 
in the direction D E , letting E be that point at 
which the line C E, if extended, would strike A. 
Now you have two right-angled triangles of the 
same angles, for, as every triangle has two right- 
angles according to geometry, and each of these 





SURVEYING. 


83 


triangles has one right angle, and the opposite 
angles at C are equal according to geometry, the re- 

Fig. 32. 



maining angles at A and E are equal, and the tri¬ 
angles are proportional, and the proportion is— 

CD : D E:: CB : A B. 

Then, if CD = 40 ft., D E = 45 ft., and CB = 60, 
we know that 45 X 60 = 2700 divided by (CD) 40 
ft. = 67 J- ft.; this is for A B, or the distance across 
the river. 

The only difficulty is in measuring your angles 
as true right angles, and this may be done by 
measuring the perpendicular, thus— 

Extend the line A B , Fig. 32, to F, Fig. 33, and 
likewise the line D E, Fig. 32, to C, as in Fig. 33. 
Now measure equal distances on the line B D, for 
the lines or offsets, B C and B H; also from D C, 





84 prospector’s field-book and guide. 


the offsets D I and D K; drive sticks in at G, H , /, 
and K. See that the distances represented by the 
dotted lines are equal, and if so, the lines ABF 
and D C are perpendicular to the line G K , and 


Fig. 33. 



your work will be well done and very nearly ac¬ 
curate. 

It is, however, well for the prospector to use a 
prism compass which will read to one-quarter de¬ 
gree. Such a compass may be had at very low 
rate, not more than three inches diameter, of light 
weight and of sufficient accuracy. The author has 
used one for many years, and traveled with it many 
thousands of miles in Asia and Africa, and can 
testify to the fact that by customary use it may be 
handled to a great degree of accuracy for horizontal 
angles. The needle is attached to the under side 
of a cord with steel engraved degrees and fractions, 
and read by a magnifying prism. 

In almost every conceivable surveying project, 
especially in running adits and sinking shafts to 
strike adits and galleries, only the best instruments 









SURVEYING. 


85 


should be used. Everything depends upon the 
most accurate measurements, and this department 
of engineering is not one that can be treated ap- 
proximately, because any error in measurement may 
result in very provoking and expensive mistakes. 

We have presented all that is required on surface 
measurements, except where it becomes necessary 
to make such accurate proceedings as may only be 
executed by use of the finest instruments, and that 
with considerable practice. Otherwise accurate 
mathematical tables are of little importance, as 
their use is based upon the presence of most ac¬ 
curate data, and without this the best methods and 
diagrams are in vain. 

This subject of mining engineering does not come 
within the range of our work, and for all mere ex¬ 
ploring as a prospector such ground-work or digging 
for examination as is necessary will readily suggest 
itself to any intelligent workman. 


CHAPTER V. 


ANALYSES OF ORES. 

For the examination of ores two kinds of analy¬ 
sis are employed, namely, the wet method , by the 
agency of liquids, and the dry method , in which no 
liquids are used, but only fluxes and heat. 

Preliminary examinations may be made at first 
with the pocket lens and a piece of steel or a heavy- 
bladed pocket-knife, the first to see if any native 
metals or any sulphides, etc., are present, and the 
second to try the softness or silicious nature of the 
mineral. If much quartz (silex) is present it will 
strike fire. 

Pulverize an average sample of the ore and use 
the blowpipe to detect sulphur, arsenic , selenium by 
the smell, on charcoal, or in the glass tube. 
Arsenic fumes have a garlic odor, selenium that of 
horse-radish. 

Use a test-tube with a little nitric acid and heat 
over a spirit flame. Add a few drops of water and 
one drop of sulphocyanide of potash—an intense 
deep red appears, deeper according to the amount of 
iron and solvency of the mineral in nitric acid. 

Try another portion in the same way, but add 
one drop of hydrochloric acid. A dense, curdy, 
white precipitate indicates silver. 

( 80 ) 


ANALYSES OF ORES. 


87 


Native gold or silver is determined by color and 
softness, as we have elsewhere stated ( see Index). 
Treat another portion in the same way with nitric 
acid, drop in several drops of strong ammonia 
water. An azure-blue color indicates copper. 

Antimony and tin are detected by the blow-pipe. 
Place the former upon charcoal with carbonate 
of soda, and brilliant metallic globules are ob¬ 
tained ; the metal fumes and volatilizes and covers 
the charcoal with white incrustations, and needle- 
shaped crystals appear. Tin appears when the ore 
is mixed with carbonate of soda and cyanide of 
potassium on charcoal, and the inner flame turned 
on—ductile grains of metallic tin and no incrusta¬ 
tions appear. 

Manganese gives amethystine beads of borax in 
the outer flame, 0 F, disappears with the inner, 1F, 
reappears with the 0 F. 

Alumina, manganese, lime, give their characteristic 
colors, or, in the last case, incandescent light before 
the blow-pipe on charcoal. Alumina heated on 
charcoal, and then touched by a half drop of proto¬ 
nitrate of cobalt, then heated strongly in the 0 
flame, gives a blue color. Magnesia so treated gives 
a faint red or pink, seen just as it cools. 

Zinc heated on charcoal with carbonate of soda 
in the reducing flame becomes metallic, and when 
oxidizing in the 0 flame gives a white oxide which 
is yellow when hot, white when cooled, and with 
protonitrate of cobalt when heated in the 0 flame a 
beautiful characteristic green color. 


88 prospector’s field-book and guide. 

Cobalt and nickel give the colors which have been 
noticed in another place under their respective 
names ( see Index). 

Uranium heated with microcosmic salt (phosphate 
of soda and ammonia) on platinum wire in the 0 
flame dissolves, producing a clear yellow glass, 
which on cooling becomes yellowish-green; in I F 
yellowish-green when hot, and green cold. But 
the analyst should remember that copper also pro¬ 
duces a green bead, but only in the outer or oxidiz¬ 
ing flame, and chromium the same, but in both 
outer and inner flames. 

The cop^r-green becomes blue on cooling, the 
chromium-green remains green on cooling. This 
will always prove the metal. 

Titanium in the presence of peroxide of iron, as 
in some titanic ores of iron and sand, gives, with 
microcosmic salt in a strong reducing blow-pipe 
flame, a yellow glass, which on cooling fades out to 
a delicate violet. 

Vanadium , dark yellow when hot, paler on cool¬ 
ing ; in I. F. brownish-red when hot, chrome-green 
on cooling. 

Mercury may be detected in almost any of its ores 
by the process described ( see Index), by heating in a 
glass tube and noting, under the lens, the sublima¬ 
tion of mercury in very minute shining particles. 

Minerals which are carbonates may be detected by 
their effervescence when touched by a drop of hydro¬ 
chloric acid, as in limestone and spathic iron ore. 
But the analyst must remember that some cyanides 


ANALYSES OF ORES. 


89 


effervesce where neither lime nor carbonic acid is 
present, and chloride of lime where there is no car¬ 
bonic acid. With these latter other tests must be 
.used, but the sense of smell will show that carbonic 
acid does not exist, the latter having no odor. 

Some sandstones have a small amount of lime 
carbonate and must be tried under the lens, as the 
bubbles are minute. But, while in these examina¬ 
tions great help is received, and many determina¬ 
tions can be made, especially in simple minerals and 
ores, there are compound ores so mixed in elements 
that the above tests fail to give satisfaction, because 
the colors are mixed and the action confused. Some 
of the elements must be moved out of the associa¬ 
tion and a separation made. This analysis is called 
qualitative, and we shall take a case of very full 
analysis of a compound ore. 

Qualitative analysis of ores where many ele¬ 
ments are present. 

There are many times when it becomes not only 
a matter of curiosity but of importance for the 
prospector to know the entire composition of the 
ore he has before him. 

With a little practice the “ wet method/’ as it is 
called, may be used by the prospector with all the 
accuracy required under the circumstances. 

I. Wet Method. 

Although for one or two elements the dry method 
is simpler than the wet method, it may so happen 
that sufficient heat can not be had. Some direc- 


90 prospector’s field-book and guide. 

tions whereby the wet method may prove of greater 
service will now be given : 

1. Pulverize an average specimen of the ore as 
finely as possible and pass the entire quantity taken 
as an assay through a sieve of 80 meshes to the inch, 
being careful that nothing is left remaining in the 
sieve, as it may be a very important part. 

2. Drop a little of the sifted ore into a test-tube, 
pour a little nitric acid upon it, add about one- 
eighth part water, warm it gently over a spirit 
flame to see if it will dissolve; if not, then add 
four times as much in bulk of muriatic acid (hydro¬ 
chloric acid). If this will not dissolve, then proceed 
as follows: 

3. Put the assay, after fine pulverization, into a 
platinum crucible. Place it in a suitably-arranged 
platinum wire triangle so that it will hang over an 
alcoholic blast lamp. When all is ready add a 
mixture of equal parts of sodium carbonate and of 
potassium carbonate, amounting in all to about four 
times the bulk of the assay, stir gently with a glass 
rod or a stiff platinum wire, and then light the 
lamp. Watch the assay, and when it begins to 
swell up withdraw the lamp, but return it when the 
swelling subsides, so that the alkalies do not throw 
yobr assay out of the crucible, which should be only 
one-half full at the beginning. With care the con¬ 
tents will soon subside, and under increased heat 
become a quiet liquid mass. Now extinguish* the 
flame, cool the crucible, remove crucible contents to 
a beaker-glass or place the crucible, with its con- 


ANALYSES OF ORES. 


91 


tents, within the beaker, and pour a little water 
upon it, add some nitric acid, or a little hydrochloric 
acid, but not the two acids together , unless you have 
only the assay, and not the platinum crucible, in 
the beaker—nitro-muriatic acid dissolves platinum. 
Warm and stir till the assay is entirely dissolved, 
except perhaps some white grains of silex. 

4. If the preceeding work has been properly per¬ 
formed, the assay is now dissolved and you are 
ready for work. Filter the contents of the beaker 
to separate any undissolved remainder, if any such 
is seen in the glass, and wash the filter-paper by 
passing an ounce or two of water through it, and 
now make preparations for the next step. It is not 
necessary, where extreme accuracy is not required, 
to wash the filter-paper perfectly free from the acids. 
But if it be necessary, then furnish yourself with a 
small strip of platinum ribbon ; clean its surface to 
a polish. If a drop of the filtrate evaporated from 
this surface shows not the least trace of sediment or 
outline, even under a lens, the filter paper is suffi¬ 
ciently washed. When the filter-paper, is to be 
burned and weighed, it must be perfectly freed from 
the acids by continuous washing. 

5. Pour ten or fifteen drops of the filtrate into a 
test-tube. Drop in three or four drops of hydro¬ 
chloric acid. If a precipitate forms it may be of 
silver; if so, it will grow dark violet on exposure 
to daylight, or more rapidly and darker in sunlight. 
Or to test more quickly, add strong ammonia, 30 to 
40 drops; it dissolves after a short time : or if it does 


92 PROSPECTORS FIELD-BOOK AND GUIDE. 

not dissolve, then it is lead ; filter and test on 
charcoal with the blow-pipe ; if it gives, with inner 
flame, a bead and yellow incrustation around, it is 
lead. Or, if none of the above results are seen, and 
yet there is a precipitate, then it is mercury. To 
prove this, add a solution of carbonate of potash and 
digest; it turns black ; filter and place it in a glass 
tube, heat gently with a blow-pipe; it volatilizes 
and condenses on the sides; examine with strong 
strong lens—it is mercury. 

6. But suppose hydrochloric acid produces no 
precipitate, though in excess and heated? Then 
there is neither lead, silver nor mercury in the 
assay, and it is not necessary to treat the ore for 
either, but proceed to the next step. It will be seen 
why we directed nitric acid to be poured on the 
r\ssay, as in No. 2. Hydrochloric acid would have 
prevented these tests as given, but you are now 
prepared for the next metals, with three less to look 
for, or with a certainty as to the presence of one or 
more of the three. 

7. The whole assay, or its solution, may now be 
used. If any precipitate occurred in the test-tube, 
treat the whole assay solution with hydrochloric 
acid, heat to boiling, and separate the precipitated 
metal or metals in the whole, as in the test-tube, by 
filtration. Wash, set the paper (filter) aside under 
cover of paper to dry, and pass hydrogen sulphide 
slowly through the filtrate until the filtrate smells 
plainly of the gas. 

8. As this gas is frequently used, make a simple 


ANALYSES OF ORES. 


93 


and cheap apparatus so that you may have a supply 
at any time, thus : Cut off the bottom of a long 
bottle * of small diameter, D , say about two inches, 
and fit it into a fruit-jar, E, as in Fig. 34. 

The top, A, should be fitted loosely, so that it 
may be removed and let air pass through. The 
cork at B must be air-tight. Fit a small tube into 
the cork after bending it in a spirit-flame—a quar- 


Fig. 34. 

C C 



ter-inch tube with an eighth-inch aperture is suffi¬ 
ciently large and is easily bent. Take an inch rod 
of iron, let the blacksmith heat it white-hot, and 
press it into a small roll of brimstone; this will give 
you iron sulphide—you need it in pieces as large 
as bullets: it melts readily against the brimstone. 
Place some cotton in the neck of the bottle, and 

* Cut a nick, with a large file, in the spot where you wish to start 
a crack near the bottom, then heat a rod, or poker, or spike-nail, 
nearly red-hot, place it on the nick, a crack starts; draw your hot 
iron and the crack will follow; when nearly cracked around pull the 
bottom off*. A glass chimney may be used, but it is rather too small 
to contain sufficient iron sulphide. 





















94 prospector’s field-book and guide. 

having fitted a plug of wood with holes in it for the 
bottom of the bottle, invert the bottle and fill it 
half full of iron sulphide lumps, fasten the wooden 
plug in the bottom, not very tightly, but tightly in 
three or four places, so that water can pass easily, 
and yet the plug be well fixed in. Put the bottle 
in its place, resting in the jar at A, and somewhat 
loosely fastened. But this must be after you have 
half filled the jar with a mixture of equal parts 
of common hydrochloric acid and rain-water (or, 
next best, well-water). Hydrogen sulphide will form 
immediately, and if you have made all connections 
perfectly, as in the figure, the gas will pass from this 
apparatus into the solution of ore in the beaker and 
precipitation will soon take place. The advantage 
' of this apparatus is that if you tie two little blocks 
of wood against the sides of the india-rubber tubes, 
C C , so as to press the sides together and stop the 
gas from flowing, the gas forming pushes the water 
out of the interior glass I), and the gas stops form¬ 
ing, but is ready at any moment to begin as soon as 
the string around the little blocks is removed. 

9. After introducing the hydrogen sulphide until 
the filtrate smells of the gas, filter and wash the 
precipitate, mark the paper containing it with the 
letter A, and put this precipitate aside for the 
present. This is the precipitate from the hydrogen 
sulphide. 

10. The filtrate. If the strip of platinum 
shows that it contains some material after evapora¬ 
tion of a few drops, proceed by adding a solution of 


ANALYSES OF ORES. 


95 


ammonium chloride (sal ammoniac), and then aqua 
ammonia to the filtrate, using about one-fifteenth 
or one-twentieth of the bulk. Then add ammo¬ 
nium sulphide so long as any precipitate is appar¬ 
ent. Let it stand awhile. This precipitate may 
contain alumina, chromium oxide, zinc, nickel, 
manganese, cobalt and iron as sulphides. It may 
likewise contain phosphates, borates, oxalates, and 
hydroflu orates of the alkaline earths (barium, stron¬ 
tium and lime). The latter we may not care for. 

11. Filter and w’asli this precipitate. Add a little 
water to the hydrochloric acid, now to be used in 
treating this precipitate. Add this diluted hydro¬ 
chloric acid in sufficient quantity to dissolve the 
precipitate and put it aside to digest. If any part 
refuses to dissolve, it is because there may be 
present cobalt, or nickel, or both ; add nitric acid 
and boil, for these metals dissolve in hot nitro- 
hydrochloric acid. Filter. Next add to the whole 
solution ammonium chloride, and excess of aqua 
ammonia. The consequent precipitate may contain 
alumina, chromium oxide, sesquioxide of iron, and 
the alkaline earths, as phosphates, etc. Dissolve 
the precipitate by digesting in caustic potash solu¬ 
tion till all is dissolved that will dissolve. Filter. 
The solution may contain alumina and chromium 
oxide; boil for some time, and if a precipitate is 
formed, it is chromium oxide ; confirm by the 
blow-pipe; it gives a green bead with borax, height¬ 
ened by fusion with metallic tin or charcoal, which 
is the blow-pipe test for chromium, 


96 prospector’s field-book and guide. 

12. Now supersaturate the solution with hydro¬ 
chloric acid and boil with excess of ammonia; * if 
a precipitate is formed it is alumina. Confirm with 
blow-pipe, as has beerrshown. What was dissolved 
by digestion with potassium hydroxide (caustic 
potash solution) has now been treated. The pre¬ 
cipitate may contain iron and more chromium 
oxide, and the phosphates, etc., of the alkaline 
earths. 

13. We will now proceed with a portion of this 
precipitate by first dissolving it in as small a quan¬ 
tity of hydrochloric acid as is possible, filter, and 
add to the solution (made as nearly neutral as pos¬ 
sible) two or three drops of ferro-cyanide of potash 
(yellow prussiate of potash in solution); a blue pre¬ 
cipitate is formed, proving the presence of iron 
sesquioxide. Wash another portion and fuse it in 
a small crucible with potassium nitrate (pure salt¬ 
petre) and sodium carbonate about equal parts. 
When [cold digest with water; a yellow solution 
results, which produces a yellow precipitate with 
acetate of lead, showing the presence of oxide of 
chromium. This double finding of chromium oxide 
(for it was found before) is due to the relative quan¬ 
tity of iron present as related to chromium oxide 
present, which will not be entirely precipitated at 
one time in the presence of iron under these circum¬ 
stances. 

14. We now go back to the solution filtered off 

* By “ excess” is meant so much that after stirring with a glass 
strip or rod, the liquid smells strongly of ammonia. 


ANALYSES OF ORES. 


97 


from the precipitate treated of in paragraph 11. 
This solution may contain zinc, manganese, nickel 
and cobalt. Digest with ammonium sulphide, wash 
the consequent precipitate and dissolve it in nitro- 
liydrochloric acid (aqua regia). It may be dis¬ 
solved upon the filter by dropping the mixed acids 
and filtering through into a clean beaker, just as it 
could have been done in paragraph 11. This is 
convenient when the precipitate adheres too tightly 
to the filter to allow of scraping it off entirely. 
Digest this clear solution with potassium hydroxide 
(or caustic potassa) precisely as in paragraph 11. 
This potassa may be put into the beaker in small 
pieces of the stick, in which form potassium hy¬ 
droxide generally is sold. 

(a) The solution may contain zinc oxide. 

( b) The precipitate may contain manganese, cobalt 
and nickel, as oxides. Pass hydrogen sulphide 
through the solution (a) until the precipitate (white 
zinc) had ceased to fall* Wash and agitate the pre¬ 
cipitate ( b ) with a solution of carbonate of ammonia. 
The precipitate which now falls is the carbonate 
of manganese —confirm this by the blow-pipe. The 
solution from this last treatment may contain cobalt 
and nickel oxides. Evaporate it to dryness, redis¬ 
solve in a few drops of hydrochloric acid, and again 
evaporate to a moist mass and divide the mass into 
two parts. Heat one portion with borax in the 
blow-pipe flame, a blue bead proves cobalt. Dis¬ 
solve the other portion in water and add solution 
of cyanide of potassium slowly; a precipitate is 

7 



98 prospector’s field-book and guide.- 

formed which, on continued adding of the potas¬ 
sium cyanide, begins to redissolve. On adding 
hydrochloric acid it is again precipitated. It is 
nickel. Confirm with the blow-pipe. 

15. In paragraph 9, paper A was put aside. 
This paper contained the precipitate holding the 
copper of the ore if any was present. Digest this 
with ammonium sulphide (or potassium sulphide). 
A solution and a precipitate are formed. The pre¬ 
cipitate may contain lead, mercury, bismuth, cad¬ 
mium, besides copper, as sulphides. The solution 
may contain gold, platinum, antimony, arsenic and 
tin as sulphides. 

16. Treat the precipitate first, by boiling it with 
nitric acid. A black or brownish residue remains 
undissolved. Take a hard-glass tube, and having 
washed and dried the black residue, introduce some 
of it into the tube and heat it. It may act in three 
ways: ( a ) it sublimes without change; mercury oxide 
was present—test with blow-pipe ; ( b ) it sublimes, 
leaving a white powder which, when moistened with 
ammonium sulphide, turns black, proving it to be 
lead sulphate; (c) it sublimes, but as a mixture of 
mercury sulphide with minute globules of metallic 
mercury , showing that through some haste or lack of 
care, mercury as sub-oxide of mercury still remains 
when it should have been entirely precipitated as 
chloride of mercury at the first (paragraph 5). 

17. We now proceed with the filtrate (obtained as 
stated in paragraph 16), from the black or brownish 
residue. Treat this with solution of carbonate of 


ANALYSES OF ORES. 


99 


potash and wash the consequent precipitate, and 
then digest this precipitate in cyanide of potassium 
in excess, while it is moist. This may be done on 
the filter after changing the beaker, since this fil¬ 
trate or solution must be kept. The insoluble part 
may contain lead and bismuth as carbonates—the 
solution may contain copper and cadmium as double 
salts with cyanide of potassium. 

18. Proceed with the insoluble part by boiling it 
with dilute hydrochloric acid. To one part of the 
resultant solution add sulphuric acid ; the precipitate 
indicates lead. To the other part, after concentra¬ 
tion by evaporation, add a large quantity of water 
—a milkiness is produced indicating bismuth. 

19. Into the solution (paragraph 17), after digest¬ 
ing with potassium cyanide, pass hydrogen sulphide 
—the precipitate , if formed, indicates cadmium —test 
it with the blow-pipe. To the solution add hydro¬ 
chloric acid— copper sulphide will be precipitated ; 
add a few drops of nitric acid, which will dissolve 
the copper sulphide, and then by adding ammonia 
in slight excess the solution has a blue color indicat¬ 
ing copper. 

20. We are now to treat the solution mentioned in 
paragraph 15. The insoluble part, paragraph 16, 
having been separated off as there stated, add to the 
solution acetic acid, and boil. If a precipitate be 
produced, collect a small portion, wash and heat it 
over a spirit-lamp upon a strip of platinum foil. If 
it burns with a bluish flame and leaves no residue 
whatever , it is sulphur and nothing more may be 


100 prospector’s field-book and guide. 

done—this part of the assay is exhausted. But if it 
leaves some residue, then several important elements 
may be present. Proceed, and to one part add a 
solution of chloride of tin (protochloride with a 
drop of nitric acid added), a purple color is pro¬ 
duced. To another part add a solution of proto- 
sulphate of iron—a brown precipitate is produced 
indicating gold in both cases. 

To another part add ammonium chloride (solu¬ 
tion) ; a yellow crystalline precipitate falls which 
marks platinum. Arsenic may be tested for by the 
blow-pipe in the ore, but if the presence of sulphur, 
in larger quantity, prevents detecting a small quan¬ 
tity of arsenic, it may be detected thus : Take a part 
of the black or brownish precipitate resulting from 
the addition of acetic acid, and mix it with three 
times its bulk of nitrate of potash (saltpetre) and 
carbonate of soda. Project this mixture, a little at 
a time, into a Berlin crucible, in which a mixture 
of the same substances has been placed and is in 
fusion over a lamp. At conclusion, digest the fused 
mass with pure water; filter; add excess of nitric 
acid and heat; now add nitrate of silver ; filter when 
cold, and add very dilute ammonia; a brown pre¬ 
cipitation on coloring marks arsenic. 

Dissolve another portion of the dark precipitate 
or residue from acetic acid in hydrochloric acid. 
Place in the solution a strip of metallic zinc—a 
pulverulent deposit takes place on the zinc, indi¬ 
cating antimony. If more proof be wanted remove 
the powder to a beaker and digest in nitric acid, 


ANALYSES OF ORES. 


101 


when a white precipitate is formed. Digest it with 
a strong solution of tartaric acid ; only a part may 
be dissolved, but filter; into the clear solution pass 
hydrogen sulphide and an orange-colored precipi¬ 
tate is formed, proving antimony. 

In the last paragraph it was found that a part of 
the precipitate was not dissolved in the tartaric 
acid ; dry it; place it on charcoal with a little 
cyanide of potassium and carbonate of soda, and 
turn the inner flame of the blow pipe upon it; it is 
reduced to metallic tin. 

In the above analysis provision has been made 
for the detection of sixteen elements. Of course, if 
no precipitates or signs appear at any one stage of 
the analysis, proceed immediately to the next, for it 
is not probable that any mineral will ever contain 
even one-half the elements mentioned in the assay, 
but the full number is given so as to reach any 
possible case. 


II. DRY ASSAYS OF ORES. 

The wet assay method having been described, we 
now give as much of the dry assay as may generally 
be called for. 

What will be first needed in the dry assay are 
crucibles, scorifiers and cupels. Crucibles for 
general purposes are made of coarse material, and 
are called Hessian. They are sold in nests of five 
or more. The only sizes of much value are those 
holding about 6 to 8 ounces. Scorifiers are flat, 
but thick, clay saucers intended to prepare the 


102 prospector’s field-book and guide. 

rough ore for the finer treatment by use of the 
cupel and in the assay furnace. The cupel is a 
little saucer of bone-ash, intended to be used on the 
floor or bottom of a heated muffle in the assay 
furnace. The muffle is a clay oven of small 
dimensions, intended to protect the scorifier and 
cupel from the coals of the furnace. They can be 
obtained at any chemical warehouse. 

An assay furnace may be made of sheet-iron ; it 
should be some 15 inches in diameter, with a grate 
near the bottom, and lined with either ordinary or 
fire brick. 

In the accompanying illustration, Fig. 35, is given 
the general form of one which has been used for 
years with perfect success. 

A plain sheet-iron cylinder (Fig. 35) 18 inches 
high and 15 inches in diameter, with draft hole at 
A, muffle hole at B, and pipe- 
hole at C, and lined, as has been 
said, with brick, will answer all 
purposes of the best assays. The 
hole at C must have a collar 
and pipe either for a chimney 
or it must enter a chimney. B 
must be provided with a flanged 
door, as also the draft hole A. 
The top may have, loosely laid 
on, only a square sheet of heavy 
sheet-iron, and the whole placed 
upon a flat stone or few bricks. Several heavy 
bars of iron nicked into the bricks will answer 


Fig. 35. 
© 


B 


D 

□□ 











ANALYSES OF ORES. 


103 


where there is no iron foundry at hand to cast a 
grating D. Charcoal or coke may be used, or, 
where the draft is strong, a hard coal. 

The crucible should be lined with charcoal finely 
pulverized and made pasty with molasses or any 
syrup. This process is called “ brasquing.” Heat 
the crucible before using, to dry out the syrup. 

For field testing a small portable assay furnace, 
using preferably some form of gaseous fuel, is of 
great advantage. Such a furnace is made by E. II. 
Sargent & Son, of Chicago, Illinois. It has the 
advantages of only weighing 7 lbs., being about 5 
by 8 inches, when set up is about 20 inches in 
height, and it packs in a space of 1 cubic foot with 
all the necessary material—the box then weighs 
ready packed, some 25 lbs. (without mortar and 
pestle); and lastly, one of the greatest recommenda¬ 
tions is that refined petroleum is used as the fuel. 
This form of fuel is much more easily obtained, and 
is less dangerous than gasoline, which is the liquid 
fuel most commonly used for assaying. 

If the object is to obtain the amount of an ordi¬ 
nary metal, such as iron or lead , pulverize the ore 
to about forty to the inch, weigh it, mix it with 
charcoal and cast the mixture, from a piece of paper, 
on the bottom of the crucible, cover it with charcoal 
an inch or two deep, drop in two or three pieces of 
brick, and place the crucible in the hottest part of 
the fire, cover all with coal and gradually increase 
the heat and keep it nearly at white heat for half 
an hour, draw it out, jar the crucible down on a 


104 prospector’s field-book and guide. 

stone to settle the melted button. When cool take 
out the contents, and the metallic iron or lead will 
be found with its slag attached. Clean the button 
and weigh it, then 

weight of resulting button y 10Q = percentage of 

weight of sample of ore 
metal in the ore. 

Scales, weights, etc. Any scales that weigh 
from J oz. to \ lb. or a greater amount will serve 
for the rough work in the field. The cheapest and 
lightest scale is one used for weighing letters, which 
weighs from J oz. to 12 ozs.: but a better scale is 
a light spring balance, weighing up to 2 lbs., and 
divided into J and J ozs. 

The sample can best be weighed by laying it on 
a sheet of paper, turning up the edges, and tying 
them with a piece of string which can be hooked 
on to the scales. 

For more delicate work, a small pair of scales 
weighing to y^oth of a grain is quite sufficient. 
Such scales may be bought at any chemical ware¬ 
house, made to pack and carry with ease and secur¬ 
ity. When in a fixed laboratory at home, the 
scales weighing to 0.0077 grain or half a milligram 
will save chemicals, time and work ; but unless the 
analyst has an absolutely true average of the ton of 
ore most carefully chosen, the smaller the amount 
of ore used the more likely is the assay to prove 
deceptive when proportioned to the ton. 

In weighing the ore it is well to make use of the 
conventional assay ton weights, as by this system 



ANALYSES OF ORES. 


105 


the number of ounces of precious metal in a ton 
of ore may be known according to the amount 
of milligrammes, etc., the button of precious metal 
weighs. The assay ton (A. T.) weighs 29.166 
grammes, or 29,166 milligrammes. 

If 1 A. T. of ore yields a button of 1 milligramme, 
a ton of ore yields 1 oz. troy of precious metal. 

SAMPLING AND PULVERIZING. 

Sampling is of the utmost importance, especially 
with gold ore, as a very small amount of gold, more 
or less, makes a vast difference in the estimated 
value of the vein or deposit. Do not take selected 
small pieces, but an average sample of the mineral 
deposit. Pulverize the specimen carefully in a 
mortar, or, in the absence of the latter, break the 
ore up into a few pieces, wrap the latter in cloth or 
paper, and powder between two hard rocks. To 
prevent fragments of ore from flying out of the 
mortar, cover the latter with a piece of paper with 
a hole in the center for the pestle to pass through. 
Quartz and similar substances will be rendered 
easier to crush by first being heated and then thrown 
into water. Pulverization for the dry method should 
never be more than 50 or 60 to the inch. Smaller 
particles are apt to be lost or separated in the 
crucible. Obtain a piece of silk bolting-cloth from 
a flour miller or from the source from which he 
gets his cloth, and select two or three grades, one 
for “wet analysis,” which may be as fine as 80 to 
the inch. Have a rim made by the tinner to tie on 


106 prospector’s field-book and guide. 

the sieving cloth, or use a cracked beaker-glass, 
cutting it off by the method we have already given. 
(See 'previous note , page 93.) 

When fragments of ore adhere to the mortar, a 
little pulverized charcoal should be stirred about in 
the mortar. 

Gold and Silver Ores. These ores require 
preparation in the scorifier. Powder the ore. Take 
about 50 grains of the powdered ore, 500 to 1000 
grains of lead shavings, according to the probable 
amount of silver, and about 50 grains of borax. 
Mix the ore with half the lead and place the mix¬ 
ture in the scorifier, spread the other half of lead 
over the contents, and finally spread the borax over 
all. Put the scorifier in the muffle, close the door, 
and heat up to fusion—then the door should be 
partly opened, the heat increased, until the oxidized 
lead (litharge) covers the scorifier. Take the latter 
from the muffle and pour the contents in an iron 
cavity or mould, separate the button and hammer 
it into the shape of a cube. It is now ready for 
cupellation, as it contains all the gold and silver. 

Cupellation. By this process the lead is simply 
separated from the gold and silver, the separation 
being effected both by absorbing and oxidizing. 
Cupels may be made by the operator, but they can 
be bought so cheaply that it is seldom worth the 
trouble to make them. 

Push a cupel into the heated muffle, place the 
cube of lead in the cupel with little tongs, and heat 
up till the lead melts; watch the lead gradually 


ANALYSES OF ORES. 


107 


wasting away until reduced to the size of the silver 
it contains, when the surface will become instan¬ 
taneously bright and nothing remains but the silver 
containing the gold. Withdraw the cupel and cool 
and weigh the ball. The gold and silver must be 
separated by the wet process, thus: Dissolve the ball 
in strong nitric acid and heat till the acid boils; a 
dark powder precipitates; filter off the dark powder, 
(it is the gold) and precipitate the silver by solu¬ 
tion of common table salt or by hydrochloric acid. 
After all is precipitated drop into the white pre¬ 
cipitate some pieces of zinc, add more hydrochloric 
acid—hydrogen gas is generated, which reduces the 
white silver chloride to powdered metallic silver. 
The gold and the silver may now be melted in 
separate crucibles, weighed and compared with the 
amount of ore used. 

In these trials the lead should first be cupelled 
for its silver, and that subtracted from the silver 
found, as almost all leads contain some silver. 

If it should be more convenient to melt the ore 
in a crucible rather than a scorifier, use the follow¬ 
ing flux : If the ore is composed chiefly of rock, pul¬ 
verize, take 100 to 500 grains of ore, red lead 500 
grains, charcoal powder 20 to 25 grains, carbonate 
of soda and borax together 500 grains—the more 
rock the more carbonate of soda, the more metallic 
bases* the more borax. Place a little borax over all 
and melt till all is liquid, requiring about 20 min¬ 
utes ; withdraw, extract the button when cool, 
hammer up to a cube and cupel. Separate the 


108 prospector’s field-book and guide. 

gold and silver as before, but remember that the 
amount of silver must be three times that of the 
gold, and if there is reason to believe that there is 
not this amount, some silver must be melted with 
the button, since the separation will not otherwise 
be complete. 

T. S. G. Kirkpatrick recommends the following- 
process of assaying gold quartz : Take 200 grains of 
ore, 500 of litharge, 6 of lamp-black and 500 of car¬ 
bonate of soda; or, 200 grains of ore, 200 of red 
lead, 150 of carbonate of soda, 8 of charcoal and 6 
of borax. Mix and put into a warmed crucible, 
and cover with half an inch of common salt. Fuse 
in a hot fire 30 minutes; cool and break the pot; 
clean the button with a small hammer. 

If the quartz is very pyritous, take 100 grains 
and calcine “ dead ” without clotting, add 500 grains 
of red lead, 35 of charcoal, 400 of borax, and 400 of 
carbonate of soda, cover with salt and proceed as 
above. In each case cupel the button. 

As the bone-ash of which the cupel is made can 
absorb its own weight of metallic oxides, the cupel 
chosen should always exceed the weight of the 
button to be operated on, so as to have a margin. 
Boil the gold prill obtained from cupelling in nitric 
acid, which dissolves the silver and leaves the gold 
pure. 

The above formulse are open to modifications by 
the operator according to the apparent richness or 
poverty of the ore to be treated, and the presence 
and character of the basic impurities. In case there 


ANALYSES OF ORES. 


109 


are oxides, a reducing agent is required; and if 
sulphides, an oxidizing agent. As a rule, employ a 
weight of litharge twice that of the ore, and of car¬ 
bonate of soda the same as the ore. These reagents 
are added to control the size of the lead button, and 
to obtain one of suitable size for cupelling. 

The presence of metals in the ore is indicated by 
cupel stains as follows : Antimony , pale yellow to 
brownish-red scoria ; sometimes the cupel cracks. 
Arsenic , white or pale-yellow scoria. Cobalt , dark- 
green scoria and greenish stain. Copper , green or 
gray, dark red or brown. Iron, dark red-brown 
Lead, straw or orange color. Manganese, dark 
bluish-black stain. Nickel, greenish stain; scoria 
dark green. Palladium and Platinum, greenish 
stain; the button will be very crystalline. Tin, 
gray scoria ; tin produces “ freezing.” Zinc, yellow 
on cupel; the cupel is corroded. 

Lead Ore. To ascertain the amount of lead in 
galena, the usual lead ore, charge the crucible with 
the powdered ore, carbonate of soda—two or three 
times the weight of the ore, three or four tenpenny 
nails on top to absorb the sulphur, and a covering 
of salt or borax. Heat to redness about 20 minutes. 
Pour the contents into a mold, and separate the 
button from the slag. 

Weight of button x 100 = percentage of metal 
Weight of ore sample 

As galena always contains more or less silver, the 
resulting button should be assayed for the precious 
metal in the cupel. As the latter does not absorb 



110 prospector’s field-book and guide. 

much more than its own weight of lead, the button 
may have to be divided into two or more portions, 
and each of these cupelled separately. 

Copper Ore. The wet assay is better than the 
dry, especially that by the burette, which will be 
given later on under “ Copper.” 

Tin Ore. If it is mixed with iron or copper 
pyrites it should be powdered and roasted, and then 
mixed with one-quarter of its weight of charcoal 
and subjected to great heat in a crucible for about 
20 minutes. Jar it as in an iron assay, let it cool, 
and pick out the button or buttons, or pour it out 
while melted. 

It may be reduced otherwise by melting the pow¬ 
dered ore with cyanide of potassium, 100 grains of 
ore to 600 grains of cyanide. Cool, extract button. 

This ore is very hard and may be powdered to 
60 to the inch. 

Mercury. These ores are easily reduced by 
simply heating and condensing the vapors in a cold 
bath as in using a retort and cool receiver. 

Antimony. Place about 2000 grains of ore pow¬ 
dered in a crucible having a hole chipped out in 
the bottom, and the hole stopped loosely with a 
piece of charcoal. Put this crucible into another 
half-way down. Then lute on the lid aiid put clay 
around the juncture of the two and put live coals 
around the upper crucible by placing some broken 
bricks around the lower one on the grate, to keep 
the coals away from it. The antimony will melt 
and leave its gangue rock in the upper crucible 
while the lower one will receive the melted metal. 


ANALYSES OF ORES. 


Ill 


Bismuth, zinc, manganese, nickel, cobalt, and 
other metals should be reduced or analyzed by the 
“ wet process” already given in this chapter. 

An excellent fire lute is made of 8 parts sharp 
sand, 2 good clay, 1 horse-dung; mix and temper 
like mortar. 


CHAPTER VI. 


SPECIAL MINERALOGY. 

GOLD. 

We shall now proceed to a more definite and 
practical treatment of these two subjects, technical 
mineralogy and economic geology, so far, only, as 
they may be of service in the work before us. 

The first suggestion which may be made is that 
the best preparation for the general study of miner¬ 
alogy is to gather a collection of the chief mineral 
substances with which the student is to come in 
contract. In many cases very small specimens are 
sufficient. As we proceed in our treatment of each 
substance it will occur to the reader what and how 
much he needs to obtain. But it should be empha¬ 
sized that no amount of study on the part of the 
student, nor of description on the part of the in¬ 
structor, can ever take the place of the actual 
specimen. 

Gold .—Gold is one of the most widely distributed 
metals, but generally speaking, accumulations of 
larger quantities of it are found only in a few local¬ 
ities. Traces of it pass from various ores into arti¬ 
ficial products, for instance, into litharge, minium, 
white lead, silver and copper and coins made there¬ 
from, etc. Minute quantities of gold (about 13 
( 112 ) 


GOLD. 


113 


grains in one ton) have been found even in sea¬ 
water, as well as in clay deposits. 

In the United States the chief gold-producing 
localities are in California, Nevada, Arizona, Mon¬ 
tana, Utah, Colorado and Alaska. In the last five 
years Alaska has averaged an annual output of gold 
of $20,000,000. Since 1880 its gold product has 
been over $140,000,000. The gold-bearing areas 
of Alaska are so extensive as to make it not improb¬ 
able that it will prove to be one of the richest gold- 
producing sections in the world. 

Supplies of gold are further derived from British 
Columbia, Nova Scotia, Mexico, and Peru and 
Brazil; from Australia (especially Victoria, New 
South Wales and Queensland), Tasmania, New Zea¬ 
land, and from Africa (Natal, the Transvaal, etc.). 
The Ural Mountains and Siberia also yield consid¬ 
erable gold. In Europe, only Transylvania and 
Hungary are of any importance. 

Gold’ occurs almost exclusively in the metallic 
state, either in situ, in quartz rock, especially along 
with quartz, pyrites and hydroferrite ; also as gold 
sand, in dust or grains, leaflets and rounded pieces 
(nuggets), in the sands of rivers or in alluvial soils, 
consisting chiefly of clay and quartz sand along 
with mica, water-worn fragments of syenite, chlorite 
slate, grains of chrome iron and magnetic iron, 
spinel, garnet, etc. In the metallic state it contains 
always more or less silver as electrum. It may be 
mentioned that from numerous analyses it appears 
that New South Wales gold is richer in silver the 
8 


114 prospector’s field-book and guide. 

farther north it occurs. Siberian, Californian and 
Australian golds contain not unfrequently osmirid- 
ium, palladium and platinum. Mexican rhodium- 
gold contains 34 to 43 per cent, rhodium. Gold 
amalgam is found in California and Columbia. The 
so-called black gold which occurs in nuggets in 
Arizona and at Maldon, Victoria, in granite and 
quartz lodes, is crystalline and silver-like when 
freshly fractured, but soon turns black in the air. 
It is bismuth-gold , with 64.211 gold, 34.398 bismuth 
and 1.591 gangue. Gold is often met with in 
native tellurium and silver telluride, sometimes in 
iron pyrites, copper pyrites, in blende, in arsen¬ 
ical pyrites and galena. To detect a content of 
native gold in pyrites bring a few drops of mercury 
into a porcelain crucible, put a perforated piece of 
cardboard in the crucible so that it rests a short dis¬ 
tance above the mercury, place a small package of 
pyrites over the hole in the cardboard, heat the cru¬ 
cible for some time and watch with the pocket lens 
for the appearance of white stains of gold amalgam, 
which on rubbing with a brush or feather becomes 
lustrous. 

Gold crystallizes in the isometric system. The 
occurrence of well-defined crystals is, however, rare, 
but they have been noted in lodes in California, 
Australia and Brazil. The usual forms are cubes 
and octahedra, with rod and plate-like forms. The 
crystals faces are frequently striated, and the crys¬ 
tals are generally rounded. Figs. 36 and 37 
represent gold crystals. Twinning gives rise to 


GOLD. 


115 


dendritic and reticulated groups, but individual 
crystal faces and edges are usually very small. 
Moss-gold, leaf-gold and wire-gold are forms occurring 
sometimes. Fig. 38 shows the finest gold dust 700 
times magnified, and Fig. 39 a reduced illustration 
of a lump of gold which was found at Forest Creek, 
Victoria, Australia. It weighed more than 30 
pounds, and was 11.33 inches long and 5.15 inches 
wide. The largest nugget of gold ever found was 
at Ballarat, Australia. It weighed over 191 pounds, 
and was 20 inches long and 9 inches wide. 

The specific gravity of gold is 16 to 19.5, accord¬ 
ing to the amount of alloy ; hardness 2.5 to 3.0. It 
is the only yellow, malleable mineral found in the 



natural state. Its color varies from pale to deep 
yellow. In some localities, such as in New South 
Wales, Australia, and Costa Eica, it is often found 
of a very light color, but it presents the same color 
from whatever direction it is looked at, and to the 
prospector this is a guiding test. Indeed one of the 
most important and useful accomplishments for 




116 PROSPECTOR^ FIELD-BOOK AND GUIDE. 

gold exploitation is “an eye for color.” Native 
gold possesses a peculiar color which is readily 
recognized, although the gold may be alloyed with 
silver or copper, and its color will in an instant dis¬ 
tinguish it in the eye of the expert from any condi¬ 
tion of pyrites, whether iron or copper pyrites. 

Gold grains will always flatten when struck with 
a hammer or between two stones, whereas other 
minerals similar in color will break into fragments. 


Fig. 39. 



Or, if the doubtful particle is coarse enough, take a 
needle and stick the point into the questionable 
specimen. If gold, the steel point will readily 
prick it; if pyrites or yellow mica, the point will 
glance off or only scratch it. 

Under the blowpipe, on a piece of charcoal, gold 
may melt, but on cooling it always retains its 
color; any other mineral will lose color, become 
blackened, or will be attracted to the end of your 
pen-knife blade, if that blade has been previously 
magnetized, and the unknown substance contains 
iron. 

Gold imparts no color to boiling nitric acid. Jt 



GOLD. 


117 


will not dissolve in nitric or hydrochloric acid 
separately, but it does dissolve in the two when 
combined, and then the acid is known as nitro- 
muriatic acid or aqua regia. Proportions: one 
nitric to four muriatic. 

But it is not always a trustworthy sign that par¬ 
ticles are gold because they will not dissolve in 
nitric acid. Some seemingly gold-colored particles 
will not dissolve in nitric acid, and yet contain not 
a trace of gold. 

The simplest instrument for the discovery of gold 
and the estimation of the value of an auriferous 


Fig. 40. 



material in which the gold is contained in a free 
state, is the ordinary miner’s pan, a circular dish of 
Russian sheet-iron, about 12 inches wide and 3 
inches deep, with sloping sides. There should be a 
slight indentation all round where the sides join 
the bottom, so as to afford lodging for the gold 
grains, and the more rusty it is the better. A fry¬ 
ing pan free from grease will answer very well on a 
pinch. The South American batea, Fig. 40, made 
of hard wood in a solid piece, and hollowed out like 
a shallow funnel, is a superior implement when in 
capable hands. Another good substitute for this 
pan is a kind of magnified shovel without handle 



118 prospector’s FIELD-BOOK AND GUIDE. 

made of linden wood* and provided with a vertical 
wall on three sides. The wooden implements 
should be slightly charred on the surface to show 
up the gold grains, and should not have been used 
to hold mercury or amalgam. 

The object of panning out, as the operation with 
the pan or batea is called, is to settle and collect at 
the bottom of the pan the heaviest portions of the 
material subjected to the test. Simple as the pro¬ 
cess of panning appears to be, dexterity is only ac¬ 
quired by considerable practice. In outline the 
operation is as follows : 

A quantity of the dirt to be washed is placed in 
the pan, sufficient to occupy about two-thirds of its 
capacity. The pan with its contents is then im¬ 
mersed in water, either in a hole or in a rivulet, of 
such a depth that the operator can conveniently 
reach the pan with his hands while it rests on the 
bottom. The object of this is to give him free use 
of both his hands for stirring up the mass, so that 
every particle may become thoroughly sodden and 
disintegrated. Of course the pan may be held in 
one hand, and its contents stirred with the other, 
but the disadvantages of such a method are obvious. 

When the dirt has become thoroughly soaked and 
permeated by the water, the pan is taken in both 
hands, one on either side, and a little inside of its 
greatest diameter, and without allowing it to emerge 
from the water, it is suspended in the hands, not 
quite level, but tipping somewhat away from the 
person. In this position it is shaken so as to allow 


GOLD. 


119 


the water to disengage all the light earthy particles 
and carry them away. When this has been con¬ 
cluded there will remain in the pan varying pro¬ 
portions of gold dust, heavy sand, lumps of clay, 
and gravel stones. These last accumulate on the 
surface, and are picked off by hand and thrown 
aside. The lumps of clay must be crumbled and 
reduced by rubbing, so as to be carried off by the 
water during the next immersion of the pan. A 
neat turn of the wrist is required to. allow the 
muddy waters to escape in driblets over the de¬ 
pressed edge of the pan, without exercising so much 
force as to send the lighter portion of the gold after 
them. At last nothing remains in the pan but the 
gold dust, with usually some heavy black sand and 
a little earthy matter. By the final careful wash¬ 
ing with plenty of clean water, the earthy matters 
can be completely removed, but the heavy iron sand 
cannot be got rid of by any method based upon its 
specific gravity relatively to that of gold. 

To remove the iron sand, one of two simple plans 
has to be adopted. If the sand be magnetic, as is 
usually the case, it may be eliminated to the last 
grain by stirring the mass carefully with a powerful 
magnet, care being taken that no particles of gold 
become mechanically suspended among the black 
sand. 

Where this is ineffectual, recourse must be had to 
blowing. For this purpose the mass of gold dust 
and iron sand is allowed to become perfectly dry, 
and small quantities of it at a time are placed in an 


120 prospector’s field-book and guide. 

instrument called a blower —a sort of a shallow 
scoop, made of tin and open at one end. Holding 
the blower with its mouth pointed away from him, 
and gently shaking it so as constantly to change the 
position of the particles, the operator blows gently 
along the surface of the contents, regulating the 
force and direction of his breath so as to remove the 
sand without disturbing the gold. Where water 
can be had, a pan is the most efficient instrument a 
man can travel with in his gold-seeking journeys. 

A crude apparatus formerly much used in Cali¬ 
fornia and Australia is called the cradle or rocker. 
This, as shown in Fig. 41, is a trough of some 7 


Fig. 41. 



feet in length and 2 broad. Across the bottom 
of this several bars are nailed at equal distances, 
and at the upper end a kind of sieve is fixed at about 
a foot above the bottom. This whole arrangement 
















GOLD. 


121 


is mounted upon rollers. To operate the apparatus 
four men are required. One man digs out the 
earth from the hole, a second supplies the cradle 
sieve with this auriferous earth, a third keeps up a 
supply of water which he pours upon the earth in 
the sieve, while the fourth keeps the machine con¬ 
tinually moving upon the rollers. The large stones 
washed out are removed by hand from the sieve, 
and the water at the same time washes the smaller 
substance through, which is slowly carried towards 
the lower end of the trough by a slight ’ inclination 
given to the whole. Thus the flow of water tends 
to keep the earthy particles in suspension so as to 
allow of their washing off, while the heavier por- 


Fig. 42. 






tions of gold are obstructed in their flow, and re¬ 
tained against the cross bars fixed to the cradle 
bottom. These are removed from time to time and 
dried in the sun, when, after blowing away lighter 
particles, the metal only further requires to be 
melted. 

A more efficient apparatus is the long tom, Fig. 
42. A tom that will serve the purpose of the pros¬ 
pector can be easily manufactured on the spot where 
























122 prospector’s field-book and guide. 

it is decided to test the ore of a newly discovered 
lode. A serviceable supply of tools must of course 
be comprised in his outfit, including one or two 
good adzes for giving a smooth plank surface to the 
side of the timber which forms the floor or sides 
of the tom. A rough but quite efficient apparatus 
can by this method be constructed in a short time. 

The tom consists essentially of two separate 
troughs, as shown in the figure. These are placed 
on an incline, or given an inclination by log or 
rock supports. The California tom is about 12 feet 
long, 20 inches wide at the upper end, and widen¬ 
ing gradually to 30 inches at the mouth. A stream 
of water flows in by the spout just over the place 
where the dirt is introduced into the upper box or 
tom proper. The dirt is constantly thrown in by 
one man, while a second is occupied in stirring it 
about with a square-mouthed shovel, or a fork with 
several blunt prongs, which is useful for pitching 
out the heavy boulders that sometimes occur, and 
for tossing back undissolved lumps of clay against 
the current. The lower end of the tom is cut off 
obliquely, so that the mouth may be stopped by a 
sheet of perforated iron. The sheet of iron should 
be closely perforated with one-half inch holes—or 
smaller if the pay dirt is very fine—about 20 inches 
square. 

The apparatus being placed on an incline amount¬ 
ing generally to 12 inches, the materials all gravi¬ 
tate with the water towards this sloping grating at 
the mouth, everything passing through it except 


GOLD. 


123 


the large stones, which gather on the grating, and 
are removed as often as necessary. Beneath this 
grating stands what is called the riffle box, into 
which all the fine matters, including the gold, de¬ 
scend. The riffle box, like the tom proper, is made 
of rough plank, and is also placed on an incline, 
but only just so that the water passing over it will 
allow the bottom to become and remain covered 
with a thin coating of fine mud. In this way 
the gold and a few of the heaviest minerals will find 
their way to the bottom and rest there, especially 
by the help of the riffle bars, which give their name 
to the apparatus. Sometimes a little mercury is 
put behind the riffles, so as to assist in retaining 
the gold, and occasionally the riffle box is supple¬ 
mented by a series of blankets, which are useful 
for catching the very fine gold. 

The tom is cleaned out periodically, and the gold 
and amalgam are panned out. The tom employs 
two to four men according to the character of the 
dirt and the supply of water. It is applicable to 
diggings where the gold is coarse, it being quite in¬ 
capable of saving all fine gold, of which at least 10 
per cent, may be estimated as lost. 

The amalgam and mercury taken out must be 
pressed through buckskin or canvas to remove the 
excess of mercury, which will run into a vessel 
placed to catch it. The remaining sponge-like mass 
of amalgam, must be retorted to extract the gold. 

In Alaska and other remote districts primitive 
methods of recovering gold are employed in partly 


124 prospector’s field-book and guide. 

developed placer districts. The miners are obliged 
to make much out of little. With implements such 
as picks, shovels, whipsaws, and canvas hose, which 
they are able to carry to the place of working, they 
build ditches, flumes and sluice boxes and install 
small hydraulic plants. 

Ground Sluicing. As the best pay dirt in some 
cases is at the bottom of creeks, it is necessary to 
remove the overlying gravel wash by some economi¬ 
cal method. The stream must first be diverted into 
a flume built up on trestle work or running on one 
side of the creek. The creek bottom being freed 
from water, the large boulders are piled along the 
banks of the stream, those too heavy to move being 
broken by sledge hammers and powder. A narrow 
channel built up of boulders is thus formed which 
serves to confine the stream and increase its velocity, 
so that on being turned back into the creek bed it is 
able to carry off material which it could not other¬ 
wise have moved. The miners often enter this 
swift-flowing stream and by the use of shovels help 
the larger rocks down stream and off the claim. 
The water is from time to time diverted into the 
flume so that the large boulders may be thrown out 
or broken up. Where the creek bed is wide this 
temporary channel continually eating its way 
downward, must be moved step by step, from one 
side of the creek to the other, then perhaps back 
again in case the gravels are deep. In this way 
the mass of gravel is disintegrated and washed away 
and the gold is" concentrated in a shallow deposit 


GOLD. 


125 


on bed rock. To clean up the bed rock, sluices are 
laid, beginning at the lowest point on the claim, 
and into these the enriched gravels are worked by 
means of wing dams and shoveling. 

Sluices. The sluices consist of a series of troughs 
formed by planks nailed together. Each sluice box 
is about 12 feet in length, tapering from a width ot 
18 inches at the upper end to 14 inches at the lower 
end, thus allowing, the boxes to fit into one another 
and a sluice of considerable length to be formed. 
Riffles of several sorts are used. An ordinary form 
is made by fitting round blocks 4 inches thick, 
sawed from logs a foot or more in diameter, into the 
boxes. Another style consists of poles placed a halt 
inch apart lengthwise in the bottom of the sluice 
box. Still a third sort is made of sawed strips ot 
wood, 2 inches or so thick, and 3 or more inches 
wide, placed crosswise, and set at an angle with the 
bottom of the box, so as to overhang on the upstream 
side. All of the riffles are held in place by wedges 
of wood, so that they can be removed for the clean¬ 
up, which begins with the uppermost set of riffles, 
the concentrates finally collecting on the lowest box. 

HydraulicJcing or hydraulic mining. In localities 
where the gulches are deep, the fall of the ground 
rapid, and the auriferous deposits of considerable 
thickness, the banks of gravel are sometimes attacked 
by jets of water under high pressure, and the earth 
washed down and carried through the sluices with¬ 
out being touched by hand. This is called hydrau- 
licking or hydraulic mining. This method is very 


126 prospector’s field-book and guide. 

effective, and under favorable circumstances, such 
as a plentiful supply of water with good fall, a very 
small amount of gold to the ton can be made to 
give paying returns. The water is conducted in 
flumes or pipes to a point where it is required, 
thence in wrought-iron pipes gradually reduced in 
size and ending in a great nozzle somewhat like 
that of a fireman’s hose. Figs 43 and 44 show the 


Fig. 43. 



arrangement. Fig. 43 exhibits the mouth-piece 
movable at A B in an ascending, and at C D in 
an inclined, direction. E is a lever loaded with 
weights, which facilitates the adjustment of the 
mouth-piece by the operator in any direction. The 
method of operating the arrangement will be seen 
from Fig. 44. ^4 is the water-distributor, B the 

nozzle, C channels for carrying off the debris de¬ 
tached from the ledge; D, piles of larger pieces of 
rock which are finally comminuted. T is a tunnel 
through which the water reaches the gutter, pro- 







GOLD. 


127 


vided with the grating F through which the finer 
stuff falls into the shallow settling basin E, and is 
distributed by blocks G, while the principal mass of 
water w T ith the coarser material passes over the 
grating F into the principal sluice in which the 

Fig. 44. 



grating H retains the larger pieces which are then 
thrown out at J. The basins E and the principal 
sluice are paved with wooden blocks or stones be¬ 
tween which mercury is placed. The amalgam 
formed is freed from admixtures in a mercury bath. 



















128 prospector’s field-book and guide. 

pressed through sail-cloth, boiled in sulphuric acid 
and distilled. 

One of the main difficulties in hydraulic mining 
is the disposal of the tailings, which may amount to 
millions of cubic yards in a year from a single 
mine. 

Dredging .—Within the last few years the use of 
dredges has been rapidly extending. A dredge is 
a flat-bottomed boat, with machinery for raising 
gravel from the bottom of a stream or pond, hoist¬ 
ing it on board, washing it over inclined tables to 
save the gold, and then throwing or dumping the 
tailings overboard at the stern. A dredge may 
thus work its way up stream, or may proceed across 
a flat plain floating in a pond, cutting out the bank 
in front of it and piling up the tailings behind. 
The latter method is known as paddock dredging. 
A continuous supply of clear water is necessary for 
washing in the latter case, as very muddy water is 
found to interfere with the gold saving. Sometimes 
suction-pumps or grab-bucket dredges are used to 
lift the gravel, but ladder-bucket dredges similar to 
those used in ordinary dredging operations are 
much more common. 

On nearly all alluvial gold fields, whether shal¬ 
low placers or deep leads, is found a stratum of 
ferruginous conglomerate, composed principally of 
rounded and angular fragments of quartz of all 
sizes, cemented together by the oxide of iron with 
which the mass is impregnated, and often so hard 
as to resist everything but blasting. This cement 


GOLD. 


129 


as it is called, overlies the bed-rock, in some places 
resting on it, in others several inches or even feet 
above it. In thickness it fluctuates, from 6 inches 
to 8 feet or more. Its character varies but little. 
It is often highly auriferous, and is worthy of special 
attention. It should he pounded to a fine powder 
and tested. 

Many particles of fine gold, notwithstanding 
their greater specific gravity, exhibit the tendency 
to float in water when undergoing a washing pro¬ 
cess. To save this fine flour or float-gold, as it is 
called, experiments have shown that by heating the 
water to the boiling-point or nearly so, these float¬ 
ing particles of gold will subside to the bottom of 
the pan or vessel. 

For lode 'prospecting a pestle and mortar should be 
carried. The handiest for traveling is a mortar 
made from a mercury bottle cut in half, and a not 
too heavy wrought-iron pestle with a hardened face. 
To get the stuff to regulated fineness a fine screen 
is required, and the best for the prospector who is 
often on the move, is made from a piece of cheese 
cloth stretched over a small hoop. It is often 
desirable to heat the rock before crushing, as it is 
thus more easily triturated and will reveal all its 
gold. Having crushed the gangue to a fine powder, 
proceed to pan it off in the same manner as washing 
out alluvial earth, except that in prospecting quartz 
one has to be much more particular, as the gold is 
usually finer. Take the pan in both hands and 
admit enough water to cover the pulverized sub- 
9 


130 prospector’s field-book and guide. 

stance by a few inches. The whole is then swurled 
around and the dirty water poured off from time to 
time till the residue is clean quartz sand and heavy 
metal. Then the pan is gently tipped and a side-to- 
side motion given to it, thus causing the heavier 
contents to settle down in the corner. Next the 
water is carefully lapped in over the side, the pan 
being now tilted at a greater angle until the lighter 
particles are all washed away. The pan is then 
once more righted and very little water is a few 
times passed over the pinch of heavy mineral, when 
the gold will be revealed in a streak along the 
bottom. In this operation, as in all others, only 
practice will make perfect, and a few practical les¬ 
sons are worth whole pages of written instruction. 

•J. C. F. Johnson * gives the following directions 
for making an amalgamating assay that will prove 
the amount of gold which can be got from a ton of 
a lode. Take a number of samples from different 
parts, both length and breadth. The drillings from 
the blasting bore-holes collected make the best test. 
When finely triturated weigh off one or two pounds, 
place in a black iron pan (it must not be tinned) 
with 5 ounces of mercury, 4 ounces common salt, 4 
ounces soda, and about half a gallon of boiling 
water. Then with a stick, stir the pulp constantly, 
occasionally swirling the dish as in panning off, till 
you feel certain that every particle of the gangue has 
come in contact with the mercury. Then carefully 


* ‘‘ Getting Gold,” London, 1897. 


GOLD. 


131 


pan off into another dish so as to lose no mercury. 
Having got your amalgam clean, squeeze it through 
a piece of chamois leather, though a good quality 
of new calico previously wetted will do as well. 
The resulting pill of hard amalgam can then be 
wrapped in a piece of brown paper, placed on an 
old shovel, and the mercury driven off over a hot 
fire. Or a clay tobacco pipe, the mouth being 
stopped with clay, makes a good retort. To make 


Fig. 45. 



such a retort, Fig. 45, take two new tobacco pipes 
similar in shape, with the biggest bowls and longest 
stems procurable. Break off the stem of one close 
to the bowl and fill the hole with well-worked clay. 
Set the stemless pipe on end in a clay bed, and fill 
with amalgam, pass a bit of thin iron or copper 
wire beneath it, and bend the end of the wire 
upwards. Now fit the whole pipe, bowl inverted, 
on the under one, luting the edges well with clay. 
Twist the wire over the top with a pair of nippers 
till the two bowls are fitted closely together, and 
you have a retort that will stand any heat neces¬ 
sary to thoroughly distill mercury. The residue, 






132 prospector’s field-book and guide. 

after the mercury has been driven off, will be re¬ 
torted gold, which, on being weighed and the result 
multiplied by 2240 for 1 pound assay, or by 1120 
for two- pounds, will give the amount of gold per 
ton which an ordinary battery might be expected 
to save. Thus 1 grain to the pound, 2240 pounds 
to the ton, w 7 ould show that the stuff contained 4 
ounces, 13 pennyweights, 8 grains per ton. 

Darton's gold test . Darton remarks that a num¬ 
ber of methods have been proposed to detect the 
minute quantities of gold occurring in rocks, etc., 
and having examined and tested eveiw method, re¬ 
commends the following as requiring but little time 
and being very trustworthy. 

Small parts are chipped from all the sides of a 
mass of rock amounting in all to about J oz. This 
is finely powdered in a steel mortar, and well mixed. 
About half of it is placed in a capacious test-tube, 
and then partly filled with a solution made by dis¬ 
solving 20 grains of iodine and 30 grains of iodide 
of potassium in about 1} ozs. of water. 

The mixture thus formed is thoroughly agitated 
by shaking and warming. Then, after all particles 
have subsided, dip a piece of pure white filter-paper 
in it, allow it to remain for a moment, then let it 
drain, and dry it over the spirit lamp. It is then 
placed upon a piece of platinum foil held by pincers, 
and heated to redness over the flame. The paper 
is speedily consumed, and after heating further to 
burn off all carbon, it is allowed to cool, and then 
examined. If at all purple, gold is present in the 


GOLD. 


133 


ore, and the relative amount may be approximately 
deduced as much, fair, little or none. There is no 
compound which would be formed from natural 
products by this method which would mislead by 
staining the ash to a color at all similar to the dis¬ 
tinctive purple of finely-divided gold. 

A variation of this test is given by Thorpe and 
Muir in “ Qualitative Chemical Analysis ” as fol¬ 
lows : 

Five or ten grains of the finely-powdered mineral 
are shaken with alcoholic tincture of iodine, pre¬ 
pared by dissolving J oz. of iodine and £ oz. of 
iodide of potassium in 1 pint of rectified spirit. 

The insoluble matter is allowed to settle, a piece 
of Swedish filter-paper is dipped into the solution 
and incinerated after drying. If the ash be purple 
in color, gold is present. To confirm the presence 
of gold, treat the ash with a few drops of aqua 
regia, evaporate to dryness at a gentle heat, and 
dissolve the residue in water. Pour this solution 
into a beaker which is set upon a sheet of white 
paper. A solution is now prepared by adding ferric 
chloride to stannous chloride until a permanent 
yellow color is produced. This solution is diluted, 
a glass rod is dipped into it, then into the gold 
solution. A bluish-purple streak in the track of the 
rod confirms the presence of gold. 

Occurrence of Gold in other Forms. Besides in the 
condition of simple native gold, this metal is found, 
as previously mentioned, in intimate mixture with 
pyrite (iron sulphide). It does not seem to be a 


134 prospector’s field-book and guide. % 

compound, but, as we have said, a mixture or 
minute association. This seems evident from the 
fact that when the sulphur is removed from the 
pyrite and the iron rusts down, the gold particles 
appear with their own color and characteristics in 
cavities of various rocks, which, when crushed or 
water-worn, release the particles or pieces to be 
washed down and mingled with sands and gravels 
of lower levels, or perhaps the beds and channels 
of rivers. This is “placer gold.” Where gold has 
not yet been thus released, it is found in association 
with iron, and especially with quartz in veins. In 
some instances the gold in quartz is disseminated 
in particles so exceedingly fine as to require the 
lens to reveal them. 

Nevertheless quartz is not the only mineral w 7 hich 
contains gold, although it is the world’s great pay¬ 
ing source of gold. Some of the other minerals 
contain it. It is found in yellowish-white, four-sided 
prisms, and in small white grains as large as a pea, 
and easily crumbles. In this condition the gold is 
amalgamated wfith quicksilver in the proportion 
of 38 gold to 57 quicksilver, and is known as 
“gold amalgam.” It is very easily tested by heat¬ 
ing upon a piece of charcoal by a blow-pipe, when 
the quicksilver volatilizes and the gold remains. 

Gold in paying quantities is found in numerous 
combinations, and must be discovered and extracted 
either chemically, by the “wet method,” or by assay¬ 
ing in the crucible by means of the cupel and fur¬ 
nace, when it cannot be separated on the spot by the 


GOLD. 


135 


blow-pipe. These nrethods are taught in any book 
upon the assay of gold. 

Geology of Gold. Native gold is found, when 
in situ, with comparatively small exceptions, in the 
quartz veins that intersect metamorphie rocks, and 
to some extent in the w r all-rock of these veins. The 
metamorphie rocks thus intersected are mostly 
chloritic, talcose and argillaceous schists of dull 
green, dark grey, and other colors; also much less 
commonly mica and hornblende schist, gneiss, 
diorite, porphyry, and still more rarely granite. A 
laminated quartzite called itacolumite is common in 
many gold regions, and sometimes specular schists 
or slaty rocks, containing much foliated specular 
iron (hematite) or magnetite in grains. 

The gold occurs in the quartz in strings, scales, 
plates, and in masses which are sometimes an 
agglomeration of cr} r stals. The scales are often 
invisible to the naked eye, massive quartz that 
apparently contains no gold frequently yielding a 
considerable percentage to the assayer. It is always 
very irregularly distributed, and never in con¬ 
tinuous pure bands of metal like many metallic 
ores. It occurs both disseminated through the mass 
of the quartz and in its cavities. 

In studying the geological aspects of this subject 
and making the practical application of our knowl¬ 
edge to the search, it may be stated that the 
orginal position of gold must have been in great 
depths. From these depths it has been brought up 
by the upheaval of the granitic rocks and perhaps. 


136 prospector’s field-book and guide. 

along with basaltic and other intrusions shot up 
from immense depths. In the course of ages the 
attrition and breaking-down of these higher and up¬ 
lifted levels, and the long-continued floods, rains 
and the waves of ancient oceans and other disinte¬ 
grating forces which produced the sedimentary 
rocks, at the same time liberated the gold which 
was incapable of decomposition. The gold thus 
found new and varied resting-places in all the sedi¬ 
mentary rocks of various ages, and in all the con¬ 
ditions which the surface might assume. 

The quartz rocks are neither igneous nor sedimen¬ 
tary, but are supposed to have been in liquid form 
as solutions of silex, which, during long periods of 
time, gradually deposited the silex and whatever 
they contained, the water disappearing by evapora¬ 
tion or absorption. 

Frequently, cellular quartz has been found with 
gold within the cells, the material which surrounded 
the gold having become decomposed, and, thus 
releasing the undecomposed gold, the latter is found 
in the cells of the quartz. Miners often judge of 
the character of stone by a superficial study. 
Quartz which is dull white in color, uncrystallized, 
and shows no traces of brownstone (decomposed 
pyrites) is called “ hungry,” and not expected to 
yield good returns. On the other hand, quartz 
which is well honeycombed from decomposition of 
pyrites, stained brown on joints and faces, and 
shows decomposed pyrites between the crystals, 
promises well. 


GOLD. 


137 


Gold, therefore, is to be expected and looked for 
in granitic regions (Fig. 46), and in those rocks and 
from those gravels and sands which owe their origin 
to such regions. The auriferous belt of California 
extends along the lower slopes of the Sierra Nevada, 
which is formed of granites, flanked by crystalline 
schists and other rocks of the Jurassic. It consists 
of quartz veins striking in the same directions as 
the beds, and containing numerous metallic sul¬ 
phides which all carry gold. It requires much 
judgment, general exploration, and knowledge of 


Fig. 46. 



Section showing the two conditions under which gold is usually found in rock 

and drift. 

The Structure of the Ural Mountains.— a. Granitic and gneiss rocks 
penetrated with greenstones and porphyrytic rocks containing gold finely 
disseminated, b. Micaceous, talcose, and argillaceous slaty rocks, supposed 
to be Laurentian and Cambrian, c. Silurian and Devonian strata, d. Car¬ 
boniferous, limestone and grits, e. Coal measures. /. Permian and newer 
rocks. G, G, G, G. Drift, filling hollows in rocks with gold, especially at 
the base of the drift. 

the region before the prospector can, with proba¬ 
bility expect to meet with gold, or before he should 
begin the search. But with a full knowledge of the 
geologic conditions of the country and acting in 
accordance with the above facts, the prospector will 
soon come upon traces of gold, if any exist. 








138 PROSPECTORS FIELD-BOOK AND GUIDE. 

In looking for indications, the prospector should 
never pass an ironstone “ blow-out ” without ex¬ 
amination, as, according to the German aphorism, 
“the iron hat covers the golden head,” or as the 
Cornish man puts it, “ iron rides a good horse.” 
The ironstone outcrop may cover a gold, silver, 
copper or tin lode. 

Besides the general instructions given above, con¬ 
siderable study should be devoted to the peculiar 
and seemingly irregular deposits of gold where it 
does not appear to have been washed down from any 
higher levels. For instance, in California and some 
other districts free gold has been found in drifts and 
sand and in the beds of streams which have not 
only been filled up, but have been buried under 
regions of sandstone or other rocks, but the whole 
country has apparently been raised, or the sur¬ 
rounding region has sunk so as not to show any 
very considerable elevation beyond where the gold 
deposits have been formed. But, even in this case, 
the general rule has been shown to be correct, for 
these deposits have been proved to be in the beds 
or channels of ancient rivers, which had either been 
dried up and overflowed by vast eruptions of lava 
or basalt, and again by floods bringing new soil and 
creating sedimentary rock, or the country has been 
raised, or subsidence of a great extent of land has 
taken place. In many cases, however, no sub¬ 
sidence has occurred, but only overflow and filling 
up through ages, and the actual sources still remain 
elevated. 


GOLD. 


139 


Such events as we have just described do not 
transpire without leaving in some parts, traces or 
features or material, which, to the practiced eye 
of a skilful prospector, are evidences of some such 
movements and changes, and he may proceed to 
make a successful opening only after he has care¬ 
fully examined a large tract of country, for it is 
from extended survey that he may the more wisely 
judge of the relation of superficial parts to the 
greater depths of even small areas. 

Those rocks which lie more immediately over the 
granite, and which, although they owe their origin 
to a sedimentary condition, have been subjected to 
heat and heated waters, as is supposed, we have 
called “ metamorphic rocks.” But they have been, 
probably, first formed from the disintegration of the 
most ancient rocks, and have brought with them 
fragments of gold. These metamorphic rocks have 
been changed from ordinary sedimentary rock by 
the action of heat and by pressure, and the influence 
of such treatment may be suspected by their appear¬ 
ance being crystalline in their composition ; that 
is, the fine grains which compose them, as well as 
the larger grains, are angular, whereas the materials 
of purely sedimentary rocks are fine without an¬ 
gular shape. The larger part of granite is supposed 
to have been metamorphic or changed, as the word 
means, or “ altered ” merely by the action of heat 
into a crystalline form or mass. 

The igneous rocks are those whose forms are due 
to having been melted and driven to the surface 


140 prospector’s field-book and guide. 

through fissures in the overlying rocks. They are 
variously composed of feldspar, hornblende, a little 
quartz, with comparatively* small proportions of 
other substances, and are called by various names 
according to the composition. The metamorphic 
granite contains quartz, feldspar, and mica; the 
igneous granite contains little or no quartz. Syenite- 
granite contains hornblende in place of mica. Some¬ 
times the mica is very black, as hornblende is, and 
in that case may be distinguished from the latter 
by its more easy cleavage, as we have shown, under 
a sharp pen-knife; this black mica is the kind we 
have described as biotite (p. 35). There is a syen¬ 
ite which contains no quartz, called hyposyenite. 
These rocks are not the original home of gold, but 
at present it is very largely in these metamorphic 
rocks that the most paying gold is to be found, more 
especially in the quartz veins which have intersected 
these rocks. One, therefore, of the most important 
studies of the prospector is to acquaint himself 
familiarly with the appearance, the locations, and 
the departures of these metamorphic rocks. In 
many places where the alluvial gold, derived from 
the gold-bearing gravels, has almost ceased to be 
worth working, there still remain sources undis¬ 
covered, and these sources may probably be traced 
back even yet to some out-crop or to some ancient 
elevation now having subsided. 

The above remarks are applicable to explorations 
for other metallic ores than gold. They apply to 
silver, and especially to tin ores, and with some 


GOLD. 


141 


modifications, to copper ores and to quicksilver, as 
we shall show. 

Gold in combination. We have been speaking 
of gold as native and alone. But it must not be 
thought that this condition is the only one in which 
paying gold is found. The combination of gold 
with various oxides and sulphides of other metals 
are very valuable, and should be studied. 

In almost all gold-bearing regions the iron sul¬ 
phides carry much gold, and in some regions the 
paying gold is found only in this substance. Hence, 
it is well for the prospector to determine the pres¬ 
ence of gold in the pyrite or whatever sulphide may 
present itself. We, therefore, state a method or 
two of determining the fact that gold exists in this 
substance. 

1. To separate gold in metallic sulphides , for in¬ 
stance, iron pyrites. Powder the sulphide as finely 
as possible. Put about an ounce into a Hessian 
crucible and heat to a very low red heat for an 
hour, or until there is very little escape of sulphur 
fumes. Remove the crucible and put its contents 
into a porcelain dish. Pour over the roasted pow¬ 
der three fluidounces of strong nitric acid, by drops, 
until all violent action ceases. Add water, 8 or 10 
fluidounces; the gold, if any, will appear as a very 
fine, black powder ; filter and dry, pick out a small 
particle of the powder and mash it upon a hard 
surface, iron or agate, in an agate mortar; if it is 
gold, it will show the gold color. A sufficient 
quantity of the dried powder may be placed upon 


142 prospector’s field-book and guide, 

a piece of charcoal, and by means of either 0 or I 
flame of the blow-pipe it may be melted, and both 
by its color and softness be proved to be gold. 

There is a difficulty in this process which the 
prospector may not be able easily to overcome, and 
that is the necessity of using the strongest nitric acid. 
If he has a little laboratory he may readily make 
his own nitric acid of sufficient power, and then he 
possesses the simplest and quickest method of treat¬ 
ing sulphides or any gold-bearing pyrites. The 
process is as follows: This acid may be made from 
common saltpetre and sulphuric acid of commerce. 
Dry the saltpetre after breaking it into small lumps 
of a half inch in diameter, carefully drop the lumps 
into a glass retort, hang the retort on a wire or 
stand, and introduce the beak into a glass bottle. 
Place the bottle in a basin of cold water and you 
may now apply the heat of a lamp, keeping the 
flame low and five or six inches off from the bottom 
of the retort. A coal-oil lamp with a short chimney 
may be used, and the heat regulated to a point at 
which brownish vapors appear in the retort. Keep 
enough acid in the retort to barely cover the salt¬ 
petre, and keep cool water in the basin, and the 
vapors come over and condense without much 
trouble. 

Stop the operation when the vapors cease to come 
over, and the mass in the retort seems to settle down 
to an even surface. Then draw out the beak of the 
retort and put the glass stopper into the bottle, and 
keep the bottle away from light and heat. Wash 


GOLD. 


143 


out the retort, and if you require more nitric acid, 
renew the operation. The retort should be tubu¬ 
lated to allow of adding sulphuric acid during the 
operation if needed. 

This acid is a yellowish-brown liquid and is 
known as “ fuming nitric acid/’ and is one of those 
very active and convenient aids in the laboratory 
which cannot readily be purchased, and, therefore, 
must generall} T be made; but so little of it may be 
used that a small quantity goes a great way, and it 
will effect a result which the strongest and purest 
chemically-pure nitric acid fails to produce. Its 
effect is to release the gold from the combination of 
iron and sulphur by oxidizing the latter as well as 
the former, and rendering them soluble in water, 
while the gold remains in metallic form of an ex¬ 
ceedingly fine black powder, as has been said. 

2. Another method of detecting and separating 
the gold, where the above one cannot be used, is 
by pulverizing the sulphide ore very finely and mix¬ 
ing it with three or four times its weight of caustic 
potash or caustic soda, and then subjecting the 
crucible, which contains the mixture, to a low red 
heat till all the contents cease agitation and become 
perfectly tranquil. Then remove the crucible, wait 
till all is cool, and then add hydrochloric (muriatic) 
acid in an amount equal to three or four times the 
bulk of the mass. To this, after standing three or 
four hours in a warm place, add the usual nitric 
acid (about an ounce), after transferring all the 
liquid to a porcelain dish, or, next best, to a beaker- 


144 prospector’s field-book and guide. 

glass. Let it stand in a warm place for about an 
hour, then add a little more nitric acid (about half an 
ounce), stir it well with a glass rod or strip of glass, 
and let it stand again for an hour or two. Examine 
carefully, and if it seems to have been dissolved 
more thoroughly than before, add a little more 
nitric acid and warm again, stirring well as before. 
If no more seems to be dissolved, then filter and 
wash the sediment in the filter and let it dry, and 
remove the filter and contents for further examina¬ 
tion. Now precipitate the gold from the filtrate by 
pouring into it a solution of ferrous sulphate. [Any 
clear green crystals of “ copperas ” (sulphate of iron) 
of the drug-store, filtered, after saturated solution 
in clean rain-water and kept in corked bottles, will 
answer this purpose.] Let the solution stand in a 
warm place for an hour, drop in a few more drops, 
and if any further precipitation takes place, add 
half an ounce of the sulphate, stir it again, let it 
remain an hour longer in a warm place till all pre¬ 
cipitation ceases. Decant the supernatant clear 
water and transfer the remainder to a filter-paper 
carefully, and a little at a time, to avoid breaking 
the filter-paper, then rinse the porcelain dish to get 
all particles upon the filter-paper, and when all the 
liquid has passed through, let it dry, and remove 
all the contents of the paper to a small porcelain 
capsule or crucible, and apply the heat of the blow¬ 
pipe to burn off the paper or any organic substance 
which may have got into the powder; the gold 
remains, which may be gathered upon charcoal and 


GOLD. 


145 


melted into a globule by the concentrated flame of 
the blow-pipe, if in small quantity. Lastly, ex¬ 
amine the contents of the filter which was laid 
aside; and, if any appearance of gold is noted, 
separate it under examination by a pocket lens. 

The high value of gold renders even a grain of 
gold to the pound of ore, if that pound is an aver¬ 
age pound in the ton, worth $80 to the ton of 2000 
pounds. Hence, a pyrite which contains a half 
grain to the half pound may prove too valuable to 
neglect. In the Brazils, in deep mines, the ore 
yields only half an ounce to the ton of ore, and yet 
it is mined at a profit.* In California a continuous 
yield of three-eighths to half an ounce of gold to the 
ton of quartz is considered profitable working, f 

It must be remembered, however, that the above 
process of extracting the gold from a pyritous ore 
does not extract with perfect accuracy all the gold 
unless conducted with more care and time than we 
have suggested, but it is sufficient to reveal the fact 
that the ore is valuable. 

3. The following method requires more time and 
care and the use of a little furnace, but will give 
very accurate results. Pulverize the ore supposed 
to contain any gold, whether pyrites or not. Heat 
it in a crucible very gradually at first, increasing 
the heat to drive off as much sulphur as possible, 
frequently stirring it and increasing the heat till 

* Makins’ Metallurgy, p. 227. 
f Davies’ Metalliferous Minerals and Mining, p. 64. 

10 


146 prospector’s field-book and guide. 

all fumes seem to have escaped. Withdraw it and 
prepare a crucible (clay or Hessian crucible), by 
dipping it in a strong solution of borax in water, 
and heating the crucible and repeating the dipping 
and heating till the crucible shows a, glazed inside. 
Then transfer all the roasted powdered ore, after 
weighing it (if you desire relative quantity), into 
the crucible, and cover it with the following mixture 
(called a flux): Six times the weight of ore of lith¬ 
arge, one of dry borax, and about twenty grains of 
charcoal pulverized. Heat slowly at first, not al¬ 
lowing much foaming, until all is quiet and the 
metal button settles down at the bottom of the cru¬ 
cible. Cool and break the crucible to extract the 
button of metal, which is now ready for cupelling. 
{For this process see p. 106.) 

Any one of these three methods of separating all 
the usual ores may readily be employed, and a little 
practice will enable the operator to be expert in 
their use. A great deal more depends upon the 
skill of the operator than upon the cost of his ap¬ 
pliances. 

Rule for ascertaining the amount of gold in a lump 
of auriferous quartz , according to Phillips : 

The specific gravity of gold is 19.000. 

The specific gravity of quartz is 2.600. 

These numbers are given here merely for conven¬ 
ience in explaining the rule ; they do not accurately 
represent the specific gravities of all quartz and 
quartz gold. (The quartz gold of California has 
not, on an average, a specific gravity of more than 
18.600.) 


GOLD. 


147 


1. Ascertain the specific gravity of the lump. 
Suppose it to be 8.067. 

2. Deduct the specific gravity of the lump from 
the specific gravity of the gold ; the difference is the 
ratio of the quartz by volume: 19.000 — 8.067 = 
10.938. 

3. Deduct the specific gravity of the quartz from 
the specific gravity of the lump ; the difference is 
the ratio of the gold by volume: 8.067 — 2.600 = 
5.467. 

4. Add these ratios together and proceed by the 
rule of proportion. The product is the percentage 
of gold by bulk : 10.933 -f 5.467 = 16.400. Then, 
as 16.400 is to 5.467, so is 100 to 33.35. 

5. Multiply the percentage of gold in bulk by its 
specific gravity. The product is the ratio of the 
gold in the lump by weight: 33.35 X 19.00 = 

643.65. 

6. Multiply the percentage of quartz by bulk 
(which must be 66.65, since that of gold is 33.35) 
by its specific gravity. The product is the ratio 
of the quartz in the lump by weight: 66.65x2.60 
= 173.29. 

7. To find the percentage, add these two ratios 
together and proceed by the rule of proportion : 
633.65 + 173.29 = 806.94. Then as 806.94 is to 

633.65, so is 100 to 78.53. Hence, a lump of aurif¬ 
erous quartz having a specific gravity of 8.067, con¬ 
tains 78.53 per cent, of gold by weight. 


CHAPTER VII. 


TELLURIUM, PLATINUM, SILVER. 

Tellurium . This rare element is occasionally 
found native, for instance, in Colorado, but more 
commonly in combination with gold, silver, lead 
and bismuth, forming minerals called tellurides. 
Native tellurium is tin-white, crystalline in struc¬ 
ture, brittle, and therefore easily reduced to powder. 
Specific gravity 6, hardness 2.5. It is very fusible, 
volatilizing almost entirety and tinging the blow¬ 
pipe flame green. White coating on charcoal. 
Soluble in nitric acid. 

Tellurides. The tellurides comprise a small, 
but interesting group, and occur under similar con¬ 
ditions of association in a few widely separated 
localities, the more abundant ores being of great 
economical value, as containing a large proportion 
of gold and silver. Even poorer ores can be treated 
by roasting, and either chlorination or cyanidation. 
In many cases attempts to concentrate have been 
unsatisfactory, as the mineral frequently slimes a 
great deal. However, concentration is said to have 
been successfully applied in Boulder Co., Colorado, 
where gold is found as a telluride in lodes through 
micaceous schists, gneissic granite, and between 
granite and porphyry. 

( 148 ) 


TELLURIUM, PLATINUM, SILVER. 


149 


The presence of a telluride is recognized by the 
purplish-red color of the solution by heating the 
powdered mineral in a tube, closed at one end, to¬ 
gether with charcoal and carbonate of soda and 
adding hot water. 

When boiled in sulphuric acid a telluride yields 
a pinkish solution. The most important tellurides 
are: 

Nagyagite, foliated or black tellurium. Streak, 
blackish lead-gray. Color blackish lead-gray. 
Luster, metallic. Specific gravity, 7. Hardness, 1. 
Sectile, flexible in thin laminae. Occurs in granu¬ 
lar or foliated masses. If the mineral is treated for 
some time in the 0. F. a malleable globule of gold 
remains. This cupelled with a little assay lead 
assumes a pure yellow color. 

Nagyagite forms a valuable gold ore in Nagyag, 
Transylvania. 

Hessite. Streak, iron-black. Color, lead to steel- 
gray. Luster, metallic. Sectile, brittle. Forms 
cubic masses of fine-grained texture. Specific 
gravity, 8.5. Hardness, 2.5 to 3. Before the blow¬ 
pipe fuses on charcoal to a black globule; this 
heated in R. F. presents on cooling white dendritic 
prints of silver on its surface; with soda is reduced 
to a globule of silver. 

Petzite. Streak, iron-black. Color, steel-gray, 
iron-black, sometimes peacock tarnish. Luster, 
metallic, Sectile, brittle. Specific gravity, 8.7 to 
9. Hardness, 2.5. Forms cubic masses of fine¬ 
grained texture, like -hessite, which it resembles in 


150 prospector’s field-book and guide. 

most physical characters, but is much denser. In 
one locality in Colorado it forms one of the prin¬ 
cipal minerals in a group of quartz veins in por¬ 
phyries traversing very coarse granites, and occurs 
in rounded masses, sometimes implanted on iron 
pyrites and irregular crystalline aggregates, which 
are occasionally coated with encrusting pseudo- 
morphs of gold. Some varieties giving 18 per cent, 
of gold have a specific gravity of 8 to 8.3 ; others 
giving 24 to 26 per cent, of gold have a specific 
gravity of 9 to 9.4. 

Sylvanite or graphic tellurium. Streak, steel-gray 
to silver-white. Color, steel-gray to silver-white, 
and sometimes nearly brass-yellow. Luster metal¬ 
lic. Sectile, brittle in thin laminae. Specific gravity, 
8. Hardness, 1.5 to 2. Colors the flame blue or 
bluish-green, giving a white incrustation and a 
dark-gray bead, which can be reduced alone after 
long blowing, or more quickly w r ith soda, to a 
yellow, malleable, metallic bead of silvery-gold. 
The proportion of gold to silver varies. In Cali¬ 
fornia, sylvanite occurs in narrow veins traversing 
porphyry. It is called graphic because of the re¬ 
semblance in the arrangement of the crystals to 
writing characters. 

Platinum. Color and streak steel-gray. Luster, 
metallic, bright. Isometric, but is seldom found in 
crystals. Hardness, 4 to 4.5. Specific gravity, 16 
to 19. As heavy as gold, and, therefore, easily dis¬ 
tinguished and separated from lighter materials. 
Before the blow-pipe it is infusible ; not affected by 


TELLURIUM, PLATINUM, SILVER. 


151 


borax, except when containing some metal, as iron 
or copper, which gives the reaction. Soluble only 
in heated nitro-muriatic acid. 

Platinum occurs in flattened or angular grains in 
beds of gravel or sand which resemble gold placers, 
and have been formed in the same way by the ero¬ 
sion of older deposits. The richest and most exten¬ 
sive platinum placers occur in or near the Ural 
Mountains in gravels about 3 or 4 feet thick and 
buried below thicker layers of barren material. 
Usually, but not invariably, the gravels are also 
auriferous, and other minerals occurring with the 
platinum are zircon, spinel, corundum, magnetite 
and osmiridium. The deposits, besides quartz 
grains, contain fragments of basic magnesian vol¬ 
canic and metamorphic rocks, such as serpentine, 
olivine rock, porphyries, etc. 

Platinum is occasionally found in the gold-bear¬ 
ing gravels of California and Oregon. Alluvial de¬ 
posits of it also occur in British Columbia, Brazil, 
New Granada, New South Wales and in many other 
localities, but the quantities derived from these 
placers are small. 

Platinum occurs in situ in serpentine in the Urals 
and elsewhere, and in other metamorphic rocks in 
various parts of the world, but the quantities so 
found are insignificant. It is also found in the form 
of sperrylite (arsenide of platinum associated with 
copper ores) in the Sudbury district of Canada. It 
also occurs in the ore of the New Rambler mine of 
Wyoming, in well-defined crystals in association 


. 152 prospector’s field-book and guide. 

with covellite and pyrite. The platinum grains 
occurring native are alloys containing iridium, 
rhodium, palladium, osmium, iron and copper. The 
chief impurities are iridium, which may form more 
than half the alloy, and iron which has been known 
to amount to 19 per cent, of the mass. Usually, 
however, the grains contain from 70 to 80 per cent, 
of platinum. 

The greater part of the annual production of 
platinum is obtained from Russia. The output, in 
1906, amounted to 210,318 ozs. Colombia produces 
about 4000 ozs. per annum, the United States a few 
hundred ounces, and Australia, Canada, Borneo, 
etc., smaller quantities. The price of platinum has 
risen in an extraordinary manner in the past few 
years. 

On April 1, 1905, it was $20.50 per ounce and it 
remained firm at this quotation until February 1, 
1906, when it jumped to $25.00 an ounce, and on 
September 1, 1906, leaped to the unprecedented 
value of $34.00 an ounce. It may be interesting to 
note that the name platinum is derived from plata, 
the Spanish word for silver, since it was regarded in 
South America at the time of its discovery (1735) 
as an impure ore of that metal. 

Platinum, like gold, does not readily combine 
with other metals, and in nature the only com¬ 
pound known is an arsenide called Sperrylite, which 
is found in very small quantities in the Sudbury 
section of Ontario, Canada. Its color is tin-white ; 
luster, bright; hardness, about 7 ; specific gravity, 
10 . 6 . 


TELLURIUM, PLATINUM, SILVER. 153 

Platinum may be distinguished by its great 
weight, by its gray color, its sectile nature, and by 
the fact that it will not dissolve in any simple acid, 
and with difficulty in nitro-muriatic acid (aqua- 
regia). It may be distinguished from lead by its 
action under the blow-pipe flame, since lead melts 
immediately, leaving a yellowish coating, while 
platinum refuses to melt under the hottest flame, 
and leaves no coating whatever. When it exists in 
the alluvial soil it may be “ panned out ” just as 
gold or other heavy metals, and even more easily 
because of its greater gravity. 

It may be found in some metal-bearing veins in 
crystalline metamorphic and syenite rock, from 
which it has been washed down, just as in the case 
of gold. In the latter condition it has been found 
more extensively than in any other. 

Its chemical test is as follows: Dissolve the 
grains of the ore in nitro-muriatic acid (4 parts 
muriatic acid to 1 part nitric), preferably with 
gentle heat, add proto-chloride of tin (solution), also 
called stannous chloride (SnCl 2 ) ; if platinum is 
present a dark brownish-red color will be produced, 
but no precipitate. 

The metal may be obtained separate from its gold, 
and in the presence of many other metals, by evap¬ 
orating the above solution of the ore in a porcelain 
dish to dryness, at a gentle heat, with ammonium 
chloride (sal ammoniac or muriate of ammonia), 
and the residue treated with dilute alcohol (one- 
fourth part water). The gold will remain in solu- 


154 prospector’s field-book and guide. 

tion and the platinum be precipitated ; the precipi¬ 
tate is to be ignited, when the platinum will be pure. 
The gold, if present, may be precipitated by adding 
a solution of ferrous sulphate, after evaporating off 
the alcohol. Ferrous sulphate is proto-sulphate of 
iron (copperas in crystals). 

Stannous chloride may readily be purchased at 
any chemist’s warehouse, but as it is easily pre¬ 
pared we give the best method as follows: File a 
piece of tin into powder and heat very hot (nearly 
to boiling) with strong hydrochloric acid in a porce¬ 
lain dish or beaker-glass, always keeping tin in the 
glass or dish, by adding tin if necessary. When no 
hydrogen gas is evolved ( i . e., no bubbles arise), 
dilute with four times its bulk of pure water, 
slightly acidulated with hydrochloric (muriatic 
acid, and filter. Keep the filtrate in a well-stop¬ 
pered bottle in which some tin has been placed. If 
you have pure tin-foil, that form of tin ma}^ be used, 
for without the presence of metallic tin the stannous 
chloride (SnCl 2 ) is in danger of changing into stan¬ 
nic chloride (SnCl 4 ) with precipitation of a white 
substance (oxychloride of tin), which renders the 
reagent unfit for use. 

Sperrylite. This is the only mineral known 
in which platinum occurs in combination with 
other elements. It is composed of platinum, 55.47 ; 
rhodium, 0.68 ; palladium, trace; antimony, 0.54, 
and arsenic, 43.23. Occurs in very small quantities 
in nickeliferous ores, containing also iridium and 
rhodium, of the Sudbury district, Canada. 


TELLURIUM, PLATINUM, SILVER. 155 

Iridium, a steel-white, extremely hard metal, 
next in specific gravity to osmium, is supplied 
partly from its alloy with native platinum and 
partly from the iridosmium w r hich occurs in the 
platiniferous gravels. It is used for pen-points and 
in jewelry, and recently in metal-plating. 

Osmium is the heaviest known metal. It comes 
from the same sources as iridium, and in the form 
of iridosmium is used for pointing tools and pens. 

Palladium is a brilliant silver-wdiite metal. It 
also occurs with platinum, but on account of its 
high price is but little used. 

Silver. — Native Silver occurs in various 
shapes, as in small grains in the rock, as wire 
silver, tree-like shapes, and also in small octahedral 
crystals, and in other forms. Color and streak, 
silver-white; when found in veins is usually tar¬ 
nished on the surface. Hardness, 2.3 to 3 ; specific 
gravity, 10.1 to 11.1, according to its purity. It is 
never found absolutely pure, but contains some 
gold and frequently a little copper. It is often 
associated with iron rocks, native copper, etc. It is 
always sectile and malleable, and in this respect 
very easily distinguished from a substance fre¬ 
quently mistaken for native silver, namely, mis- 
pickel , which is an arsenide of iron, having very 
much the appearance of silver, but is always brittle. 

Before the Blow-pipe, on charcoal, native sil¬ 
ver is distinguished from tin, zinc, antimony, or 
bismuth, by the fact thas it melts and leaves no 
whiteness or any other appearance of oxide upon 
the coal around the globule. 


156 prospector’s field-book and guide. 

Tin will leave a white film, and lead a yellow, 
zinc a yellow which whitens on cooling. But silver 
leaves no film or cloud of any kind upon the coal. 

Chemical Test of Silver : Dissolve the metal in 
nitric acid in a test-tube, preferably with the heat of 
an alcohol flame, but not to the boiling point. 
Add an equal amount of pure water (clear rain 
water will answer), then drop in several drops of a 
solution of common table salt or muriatic acid. If 
a cloudy white precipitate occurs which settles and 
blackens after exposure of a few seconds to sunlight 
or a few minutes to daylight, the substance is silver. 

It should be remembered at this point that this 
test is for silver alone, since lead and mercury are 
also precipitated as a white cloud by the same solu¬ 
tion, but neither blackens by exposure to the light. 
This distinguishes silver. If, however, further 
proof is needed, drop into the test-tube strong 
ammonia water; the precipitate is dissolved if it is 
that of silver; it is not if it be of lead, and it is 
blackened by the ammonia if it is mercury. 

If there is much copper in the silver it may be 
detected by dipping a clean strip of polished iron 
or steel into the solution, for the metallic copper 
will immediately appear upon the surface of the 
iron. 

It must not always be supposed that native silver 
is metallic or white in appearance, for it is readily 
tarnished by sulphur, and the proximity of sulphur 
in other minerals or in water may greatly discolor 
the native silver. 


TELLURIUM, PLATINUM, SILVER. 157 

Comparatively speaking, very little of the silver 
of the mines is derived from native silver. Most 
of the silver of commerce is obtained from some 
of the minerals named below, which are combina¬ 
tions of silver with other metals, and with sulphur 
or chlorine, as sulphides of silver, etc., in which 
condition they bear no resemblance to native silver. 

But in all silver minerals of any commercial 
value, the already mentioned tests are usually suffi¬ 
cient to detect the existence of silver. 

Other forms in which silver is found are— 

Silver Sulphides are very largely associated 
with lead sulphides or galena, and sometimes called, 
when pure: 

Silver Glance or Argentite. This is found in 
masses, but when crystallized it occurs in cubes or 
octahedral forms. When freshly broken it has 
a metallic luster, otherwise it is of a dull gray or 
leaden appearance. It is soft and sectile, and its 
“ streak ” or the color of its powder is the same as 
that of the mineral itself, and rather shining. 
Chemical composition: Silver, 87; sulphur, 13. 
Hardness 2 to 2.5. Specific gravity 7.1 to 7.4. 

The ore is soluble in nitric acid, and on adding 
common salt to the solution, a white curd is thrown 
down which blackens on exposure to sunlight. It 
is very fusible at the temperature of an ordinary 
flame, giving off an odor of sulphur when heated. 
Before the blow-pipe on charcoal, with or without 
carbonate of soda, it yields a white globule of me¬ 
tallic silver which can be flattened under the 
hammer, 


158 prospector’s field-book and guide. 

The ore in an amorphous state is most common 
in earthy vein-stuff (called metal azul) or with 
pyritic minerals, especially galena. It is rarely 
recognizable by form or physical character, as rich 
quartz only differs from ordinary by its pale bluish- 
gray tint, and argentiferous galena is, as a rule, 
undistinguishable by sight from that containing no 
silver. 

Cerargyrite or horn silver. The mineral 
known under this name is a chloride of silver oc¬ 
curring in veins of clay slate with other ores of 
silver, usually only in the higher parts of these 
veins. With ochreous brown iron ore, with several 
copper ores, etc. Luster, waxy, resinous. Fracture, 
conchoidal. Color, greenish-white, pearl-gray, 
brownish, dirty green, and on exposure brownish 
or purplish. It yields a gray, shining streak. It 
is translucent on the extreme edges and has a waxy 
appearance. It cuts like horn or wax, and on an 
outcrop looks like dirty cement. It contains 75.3 
per cent, silver, and 24.7 per cent, chlorine when 
unmixed or nearly pure. 

A polished piece of iron may be slightly coated 
with silver if a piece of horn silver is moistened and 
rubbed upon the iron. 

Horn silver is very easily fusible, melting in the 
flame of a candle. Heated with carbonate of soda 
on charcoal, it yields a globule of metallic silver. 

This mineral, in various degrees of impurity, 
forms a very large part of the silver-bearing ores 
of some mines in South America, as well as in the 


TELLURIUM, PLATINUM, SILVER. 159 

Western States and Territories of the United States. 
It is a valuable ore. 

Stephanite or Brittle Silver Ore is a silver 
sulphide with antimony , and is found in masses and 
sometimes in rhombic prism crystals in veins with 
other silver ores. It is easily distinguished from 
silver sulphide (or glance) by the fact that it is 
brittle, while the glance, if fairly pure, may be cut 
with a knife into chips without breaking. 

This ore is black or iron-gray, has a hardness of 2 
to 2.5 and a specific gravity of 6.2 to 6.3, and when 
pure contains 71 per cent, of silver, the rest being 
antimony with some other admixtures, usually iron 
or copper. It is an abundant silver ore in the 
Comstock Lode, Nevada (Figs. 47, 48), in the Reese 
River and Humboldt and other regions, and at the 
silver mines in Idaho. 

On charcoal, under the blow-pipe, it decrepitates 
and coats the coal with a film of antimony (anti- 
monous acid), which, after considerable blowing, 
turns red, and a globule of silver is obtained. 

Ruby Silver. Several ores of silver contain 
arsenic and antimony as well as sulphur. The 
most important of these are the dark-red, sometimes 
black, silver ore called Pyrargyrite, which con¬ 
tains 59.8 per cent, silver, 17.7 per cent, sulphur, 
and 22.5 per cent, antimony ; and the light-red 
silver ore, known as Proustite, with 65.5 per cent, 
of silver, besides sulphur, and may have a grayish 
appearance. Proustite has been found in masses of 
several hundred pounds weight at Poorman Lode, 


160 prospector’s field-book and guide. 


Idaho (Dana). In Mexico it is worked extensively 
as an ore of silver. 

Both these minerals occur massive, granular or 
as prismatic crystals. They resemble each other 
closely in their characters, their hardness being 2 
to 2.5, and the specific gravity of pyrargyrite 5.8, 
and that of proustite 5.6. Both have a red streak 
and an adamantine and submetallic luster. 

Before the blow-pipe, pyrargyrite gives off dense 
antimony fumes, while proustite yields arsenical 
fumes easily recognized by their garlic odor. 
Heated on charcoal with carbonate of soda both 
minerals afford a globule of metallic silver. 

Nitric acid extracts the silver from these ores, 
forming a solution, in which salt throws down a 
white curd, blackening on exposure to sunlight. 

Bromic Silver or Bromyrite. This is a com¬ 
mon ore containing bromine 42.6 per cent, and 
silver 57.4 per cent. 

There are other minerals in which silver occurs, 
but they are only exceptions or rare, and if one is 
acquainted with those mentioned above, he will 
very likely detect the rarer silver minerals, which 
are not ores in the usual sense, but they may lead 
when discovered to valuable results. 

Valuing silver ores. A simple, but rough, method 
is sometimes adopted of testing the value of ores 
from day to day when chlorides are the minerals 
chiefly worked, by powdering the ore in the mine, 
mixing it with a solution of hyposulphite of lime 
which dissolves the chloride, and then adding 


TELLURIUM, PLATINUM, SILVER. 161 

sodium sulphide, which forms a dark-colored pre¬ 
cipitate if much silver is present. It is evidently 
impossible to estimate in this way the content of 
silver, but it affords a very good test whether the 
ore is of value or not. 

Reference may here be made to what are called 
argentiferous minerals, comprising ores of lead or 
copper, in which more or less silver is present. 
These may be enumerated as follows: Galena (sul¬ 
phide of lead); bournonite (sulpho-antimonide of 
lead and copper); tetrahedrite (antimonial gray 
copper); tennantite (arsenical gray copper); mis- 
pickel (arsenio-sulphide of iron); zinc-blende (sul¬ 
phide of zinc). 

These minerals will be described later under the 
headings where they belong. When argentiferous, 
they do not give evidence of the presence of silver, 
unless they are submitted to the process of assay. 
A very simple test for the presence of silver is given 
by Charles H. Aaron * as follows: The ore should 
be ground fine, and then a few ounces are mixed 
with about one-tenth of its weight of salt, and one- 
twentieth of copperas. This is placed in an old 
frying pan and heated gently so long as a smell of 
burning sulphur can be noticed, the mass being all 
the time stirred with a thin bar of iron. After all 
the sulphur has been driven off, the heat is in¬ 
creased for a few minutes to a light red, and the 
mass stirred until it swells up and becomes sticky, 

* Practical Treatise on Testing and Working Silver Ores, 

11 


162 prospector’s field-book and guide. 

care being taken not to fuse the ore. The mass is 
then taken out and allowed to cool on a rock, and 
after a little more salt has been added, and the ore 
mixed with water to the consistency of mortar, a 
strip of sheet copper previously cleaned, is inserted 
and left there for ten minutes. The copper strip is 
then removed, washed in clean water, and, if any 
silver is present, it will be coated with a white sub¬ 
stance which will be heavier or lighter according to 
the richness of the ore and, if very rich, will appear 
gray and rough. The frying pan should be 
smeared with clay or mud, and dried before being 
used. 

Geology of Silver Ores. The most valuable 
ores occur in the earlier or more ancient rocks, such 
as the granitic or gneissoid rocks, clay slates, mica 
schists, older limestones, and in the metamorphic 
rocks. The remarkable geologic conditions under 
which silver ores and veins occur may be under¬ 
stood more readily by the following diagrams than 
by any descriptions without them. (Figs. 47 and 
48.) 

In the diagrams the rocks are seen tilted up from 
the horizontal position to one nearly vertical, but 
evidently after this uplifting the trachytic dykes 
were shot through the masses of conglomerate. 
The lodes bearing silver are represented by contin¬ 
uous double lines, and the dykes by dotted vertical 
lines. The entire distance represented from Sutro 
to the west end of the diagram is about 5J miles, 
pn a course east and west, being the same as that of 


TELLURIUM, PLATINUM, SILVER. 163 

the Sutro tunnel upon this branch, which joins or 
intersects to the north and south branch of the 
tunnel at the Comstock lode. 

In order that the superficial nature of the country 
may be understood, we have given the north and 
south sections of the same region, showing some of 
the mines by vertical black lines and by shaded 
spaces where the mines have been worked more or 
less extensively. (Fig. 48.) 

The north and south sections exhibit the hilly 
surface, and fully illustrate the work of the pros¬ 
pector who would become acquainted with the min¬ 
eral deposits of a similar region. 

It will be seen in the east and west sections that 
all the lodes out-crop. (Fig. 47.) The non-metallic 
substances of these lodes are quartz, fluorspar, with, 
perhaps, some chlorides or sulphides ; the latter may 
be metallic, and there may occur some traces of 
gold and silver, perhaps also of antimony, lead, etc. 
The wisest course, therefore, is for the prospector, 
after having settled in which direction the strike or 
course of the strata runs to make an examination 
directly across the strata, the chief object being to 
learn the nature of the rocks of the region, and, at 
the same time, to detect the outcropping of any 
lodes or dykes. 

His object is to become acquainted with the strata 
by means of the loose material, the fragments, or 
small outcropping rocks, where he cannot penetrate 
beneath the soil. 

It may become necessary to traverse a great dis- 


MountDavidson 1827 ft. 
„ above the sett level 


164 prospector’s field-book and guide. 



Syenitic rock. Conglomerate rocks with dykes of Feldspathic rocks. 

trachytic rock. 

SECTION ACROSS THE COMSTOCK LODE AND SURROUNDING STRATA. EAST AND WEST. 








































TELLURIUM, PLATINUM, SILVER. 165 

tance before any certain information may be gained, 
and where the hill surfaces are covered with soil, 
the ravines will frequently disclose the nature of 
the rock. 

It will be noticed that the Comstock Lode begins 
immediately adjoining the syenite rock, and at the 
outcrop extends six or eight times the actual thick¬ 
ness of the lode below. It is also apparent that the 
lodes generally, at least in this region, bifurcate 
near the surface, even in the syenite, and when an 
outcrop has been discovered, the probability is that 
not far off another outcrop of the same lode may be 
found (Fig. 47). 

The Comstock Lode has been traced for four or 
five miles north and south, but the values of the 
deposits are not uniform. The great bodies of ore 
may be seen in the north and south section where 
the excavations are largest, as around the Savage, 
and from the Exchequer to the Crown Point prop¬ 
erties. But this whole region is filled with dykes 
and lodes for miles beyond the Comstock Lode, 
which lies on the eastern slope of a range of hills 
running somewhat parallel, but about fifteen miles 
east of the Great Sierra Nevada range, south of the 
Pacific Railroad, and between the lakes Begler and 
Carson in the western part of the State. 

In the Tonopah district, the rock is apparently 
similar in composition to that of the Comstock, and 
probably of the same age. The most important 
veins occur in the early andesite, and do not extend 
into the overlying rocks. The ores are in the form 




, 166 prospector’s field-book and guide. 
























































TELLURIUM, PLATINUM, SILVER. 167 

of quartz veins. These veins carry gold and silver 
in the proportion of about 1 part of gold to 100 of 
silver by weight. They are usually free from base 
metal; no lead, arsenic, etc. has been detected. In 
some places there is a little copper, in others none. 
Silver is found in the form of chloride, sulphite (ar- 
gentite), and ruby silver. 

In the east of Nevada, at the Eureka Mines, the 
ores are found in a bed of limestone overlying the 
granites, quartzose slates and metamorphic rocks 
of great thickness. The limestone containing the 
ore is about 300 feet thick. But while the imme¬ 
diate geology varies from that of the Comstock, the 
general facts are the same, namely, that the silver¬ 
bearing lodes are in or very near the granites or 
earliest rocks. In this case the overlying rocks, 
though limestone, are dolomitic, containing from 
36 to 46 per cent, of carbonate of magnesia, and the 
mineralized belt of limestone, or that containing 
the ores, is very much broken, and in some places 
apparently crushed, as if it had been subjected to a 
grinding process, and then partly rejoined by the 
cementing power of calcareous matter deposited 
from solution in percolating water. 

A peculiarity in this last decribed limestone is 
found in the large caverns which occur along the 
course of mineral deposit. On the floors of these 
caverns are found beds of ore which seem to have 
dropped from their position in the limestone, as 
that has been dissolved out and carried off where 
the fissures easily permitted the percolating waters 
to pass rapidly away. 


168 prospector’s field-book and guide. 

The geology of this region appears to be in the 
order of granites, quartzose slates and metamorphic 
rocks of great thickness, limestones containing 
segregations of ore, calcareous shales, and these 
surmounted by limestones also of great thickness. 
The special region to which this geological series 
refers is the Ruby Hill mines. 

The Emma Mine, with many others, is situated 
still further east, in the Wahsatch range of moun¬ 
tains, which runs north and south about twenty 
miles east of the Great Salt Lake. This mine is 
about the same distance southeast of the Great Salt 
Lake. The adjacent rocks of this mine are granite, 
in massive beds, dipping from 50° to 70° eastward. 
This is overlaid by quartzites of a reddish color, 
then occurs a series of slates, upon which are thick 
beds of white limestone, and these pass rapidly into 
the carboniferous dolomitic limestone. It is in this 
last limestone that the ore deposits of the Emma 
and adjacent mines are worked. 

It is a fact, however, that the ores are mainly 
composed of silica and lead of which there is over 
70 per cent. The amount of silver is about 0.40 to 
0.50 of 1 per cent, according to some analyses. A 
sample amount of 82 tons, gross, yielded 156 ounces 
of silver. 

These mining districts present the general geo¬ 
logic conditions in which the silver ores are found 
in these and other States and Territories, and the 
prospector should expect to find surface indications 
accordingly, but modified more or less by exposure 
to weather. 


TELLURIUM, PLATINUM, SILVER. 169 

Although from the preceding illustrations, silver 
is shown to be found both in the very early groups 
of rocks and in the carboniferous limestone, the 
latter is the exception, as it appears to be found 
there only when that limestone has occurred with 
little or no separating horizons from the earliest 
rocks. 


CHAPTER VIII. 


* COPPER. 

Copper occurs both native and in a compound 
state. 

Native Copper is found in various forms, in 
grains, strings, plates, and even in octahedral crys¬ 
tals. Color, copper-red, but ofter tarnished. Duc¬ 
tile and malleable. Streak shining; hardness 2.5 
to 3. Specific gravity, 8.5 to 8.9, according to 
purity. Frequently carries silver. Tested by the 
blow-pipe it yields in small quantities a blue tinge 
to almost black in the borax bead, according to 
quantity used and the kind of flame, whether inner 
or R or outer or 0, the latter giving blue color, the 
former giving the copper color or metallic opaque 
brown. 

Native copper dissolves readily in nitric acid, 
and if ammonia be added the solution becomes 
green, or greenish-blue if ammonia be in excess. 

In the absence of any chemicals or a blow-pipe, 
the mineral, when containing native copper, or 
when only a compound containing copper, may be 
tested by heating it either in the mass, or, better, in 
powder, and when hot, dropping it into some salty 
grease and then putting it in a flame or upon burn- 
(170) 


COPPER. 


171 


ing charcoal, when the characteristic green color 
will appear in the flame with great distinctness. 

Moreover, if the mineral contains copper in con¬ 
siderable quantity and it is dissolved in nitric acid, 
the copper will be deposited immediately upon a 
strip of polished iron or upon the end of a knife 
blade, if either be dipped into the solution. 

The natural combinations of copper are almost 
endless. Not less than a hundred mineral species 
may be regarded as copper ores from the practical 
miner’s point of view, i. e. y possessing economic 
value, and there are probably as many more which 
are not yet utilized. As might be expected the 
range of chemical associations is equally wide, em¬ 
bracing sulphides, antimonides, arsenides, oxides, 
chlorides, bromides, iodides, carbonates, sulphates, 
phosphates, silicates, arseniates, simple and com¬ 
pound, hydrated and anhydrous, in almost every 
degree of variety. 

Below several of the more important ores of 
copper are mentioned, and also some copper min¬ 
erals which, to the prospector, will be suggestive 
that the more important ores are not far off. 

Cuprite, Bed Copper Ore 1 or Ruby Copper. 
Occurs massive, granular, and earthy. Streak, 
shades of brownish-red, shining. Brittle. Color, 
deep crimson, cherry-red. Luster adamantine or 
submetallic; or again it may be dull and earthy. 
Sometimes weathered to an iron-gray on the surface. 
Hardness, 3.5 to 4; specific gravity, 6. Composed 
of copper, 88.78 per cent., the remainder oxygen, 
when pure. 


3 72 prospector’s field-book and guide. 

Before the blow-pipe, on charcoal, it yields a 
globule of metallic copper; with borax bead gives 
the indications of copper. Dissolves in hydrochloric 
acid, giving a brown solution which, when diluted 
with water, deposits white insoluble cupric chloride. 
In nitric acid it forms a blue solution. Sulphuric 
acid decomposes it into cupric oxide (CuO) and 
metallic copper, the former passing into solution as 
cupric sulphate, while the latter is undissolved. 

Cuprite occurs in granite and slate with copper 
ores and galena and forms a valuable source of the 
metal. The massive variety is known as tile ore; 
brick ore is a mixture of copper and limonite. The 
fibrous variety is known as plush copper ore. 

Chalcocite, Copper Glance or Vitreous Cop¬ 
per. Massive ; slightly sectile. Color bluish-lead 
gray, brownish ; brilliant when fresh ; black and 
dull, on exposure to sunlight tarnishing to blue or 
iridescent. Streak, blackish-grav, sometimes shin¬ 
ing. Hardness 2.5 to 3 ; specific gravity 5.5 to 5.8. 
Composed of copper 77.2 ; sulphur 20.6, and some¬ 
times a little iron. It is fusible in a candle flame. 

Before the blow-pipe it gives off an odor of sul¬ 
phur. When heated on charcoal, a malleable glob¬ 
ule of metallic copper remains, tarnished black, 
but rendered evident on flattening under a hammer. 
With borax bead it gives the indications of copper. 
Dissolves in nitric acid, forming a blue solution. 
These tests distinguish it from sulphide of silver. 
Occurs with other copper-ores. 

Tetrahedrite or Gray Copper Ore. Brittle; 


COPPER. 


173 


steel-gray or iron-black, sometimes brownish ; streak 
between steel-gray and iron-black, sometimes brown¬ 
ish ; hardness, 3 to 4 ; specific gravity, 4.75 to 5.1. 
Composed of copper 38.6, sulphur 26.3, and fre¬ 
quently antimony and arsenic, zinc, iron, silver, 
etc. It frequently contains silver, and sometimes 
as much as 25 to 30 per cent. 

Before the blow-pipe on charcoal it fuses, gives 
an incrustation of antimonious, and sometimes 
arsenious, acid, oxide of zinc and oxide of lead. 
Arsenic may be detected by its odor on heating the 
incrustation in R. F. or fusing with soda. Oxide 
of zinc gives a green color when heated with nitrate 
of cobalt solution. The iron and copper in the 
residue are found either by fluxes (on platinum) or 
by reduction with soda. Silver is determined by 
cupellation. 

Tetrahedrite is soluble in nitric acid, arsenious 
and antimonious acids separating. The solution 
becomes blue from copper by adding ammonia in 
excess, and cloudy with hydrochloric acid when 
silver is present. 

Tetrahedrite occurs with copper pyrites, galena 
and blende. It is worked for copper and occasion¬ 
ally for silver. 

Chalcopyrite or Copper Pyrites. Massive. 
Color, brass-yellow, when fresh, gold-yellow when 
tarnished. Luster, sub-metallic; brittle, slightly 
sectile. Streak, greenish-black, unmetallic. Hard¬ 
ness, 3.5 to 4, specific gravity, 4.15. Composed of 
copper 34.6, sulphur 34.9, iron 30.5. Before the 


174 prospector’s field-book and guide. 

blow-pipe it fuses with intumescence and scintilla¬ 
tion to a rough magnetic globule. When powdered 
and roasted at a low heat, it is converted into a 
fritted mass, giving reactions of copper and iron 
with fluxes. With soda on charcoal, gives a globule 
of metallic iron and copper. It is sometimes mis¬ 
taken for gold, or iron, or tin pyrites. But it is 
brittle, while gold is not; it will not strike fire, as 
does iron pyrites ; and it may be distinguished from 
tin pyrites by the film that the latter leaves on the 
charcoal, while copper pyrites leaves no residue 
under the blow-pipe. It occurs in granite and slate 
in lodes or veins, and is a valuable ore of copper. 

What is called peacock ore is only pyrites coated 
with oxide and exhibiting iridescent colors. By 
leaving a piece of clean yellow copper pyrites in 
water for some time it will become coated in this 
way. 

Chrysocolla or Silicate of Copper. Accom¬ 
panies other copper ores, occurring especially in the 
upper part of veins. It is a bright green or bluish- 
green mineral, scarcely worthy of being called an 
ore, although it contains from 35 to 40 per cent, 
copper and a large amount of silica. It is a second¬ 
ary deposit. Its hardness is 2 to 4, and specific 
gravity 2 to 2.3. Its only significance to the pros¬ 
pector is that it may be associated with true ores. 
Its powder (streak) is white, while the mineral itself 
is green, this being due to the quartz or silex in it. 
When dissolved in nitric acid a precipitate is left, 
which distinguishes it from malachite, the latter 


COPPER. 


175 


being quite dissolved. Before the blow-pipe with 
soda it gives a bead of copper. 

Black Oxide of Copper is usually found on the 
surface. Soils the fingers when pulverulent. It is 
a result of decomposition of copper ores, as a deposit 
on surface of copper pyrites. It occurs in masses 
of a dark, earthy appearance, sometimes in minute, 
shining particles. If the dusty powder be rubbed 
between the fingers and dropped on a flame, the 
latter will be colored green. Soluble in ammonia ; 
solution azure blue. 

Malachite or Green Carbonate of Copper, 
has a fibrous structure nearly opaque, and is of an 
emerald-green color, and contains about 57 per 
cent, of copper. Streak, paler green than the color. 
Hardness 3.5 to 4 ; specific gravity 3.6 to 4. Com¬ 
monly found near the surface of veins containing 
copper ores. 

Before the blowpipe it becomes blackish. With 
borax it yields the usual blue-green bead, and on 
charcoal is reduced to metallic copper. It com¬ 
pletely dissolves in nitric acid, and thus it may be 
distinguished from silicate of copper, which has 
nearly the same color and will not dissolve. 

Azurite or Blue Carbonate of Copper is 
chiefly used for ornamental purposes. It is of a 
deep cobalt-blue color sometimes transparent, brittle. 
Streak bluish ; hardness 3.5 to 4.5 ; specific gravity 
3.7 to 4. Can be scratched with a knife. It 
blackens when heated. On charcoal it is reduced 
to a globule of pure copper. With the borax bead 


176 PROSPECTORS FIELD-BOOK AND GUIDE. 

it gives the indications of copper. It is soluble in 
nitric acid with effervescence, forming a blue solu¬ 
tion. 

Variegated Copper Pyrites (Bornite or Erubis- 
cite): Usually massive, of a copper-red to a pinch¬ 
beck brown color, and a blackish to lead-gray 
streak. Hardness 2.5 to 3, specific gravity 5.5 to 
5.8. It contains about 55.5 per cent, of copper, 
28.1 per cent, of sulphur, and 16.4 per cent, of iron. 
Before the blow-pipe it gives a bead of copper. 

But the minerals above mentioned are by no 
means the most important as regards the commer¬ 
cial supplies of the metal; in'fact, in that light they 
may almost be disregarded so far as affording any 
considerable proportion of the total yearly output, 
though, of course, deposits of these ores are profit¬ 
able. The bulk of the world’s consumption of cop¬ 
per is furnished by ores of the lowest grade, ranging 
from little more than J to perhaps 5 per cent., 
though rarely more than 3 to 3J per cent. Thus 
the ores of Devon and Cornwall are worked for 1J 
to 2 per cent, copper; those of Cheshire, for less than 
1J per cent.; those of Mansfeld, Germany, for little 
over 2J per cent.; those of Rio Tinto, Spain, for 2£ 
to 3J per cent.; those of Maidenpec, Servia, for 2 to 
3 per cent.; and, overwhelmingly the most abun¬ 
dant producers, those of the Lake Superior region for 
as little as 0.65 per cent. 

Formerly the world’s supply of copper was drawn 
from the rich ores, containing up to 40 per cent, 
of metal as mined, and further explorations may 


COPPER. 


177 


again reveal in the future similar deposits to re¬ 
place those now exhausted ; but at present and in 
the immediate future reliance must be placed on 
the enormous low-grade ore-bodies now being 
worked, especially in North America. Alaska is 
proving to be a great copper country, and in 1906 
9,000,000 pounds of copper were exported from 
there. The best known, and probably the richest 
copper belt occupies a strip nearly 100 miles long 
and of varying width along the southern base of the 
Wrangell Mountains. Throughout this zone, in 
the drainage basins of the Chitina, the Kotsina, 
and the Cheshnina, there are scattered deposits 
of copper ores. In 1907 and 1908 Alaska produced 
nearly 12,000,000 pounds of copper. 

The geology of copper is more varied than that 
of many other metals, as it occurs in rocks of almost 
every age. In Cornwall the slates are more pro¬ 
ductive than the granites, while in our mines in the 
Eastern States the new red sandstone, the carbon¬ 
iferous limestone, and Silurian rocks furnish copper. 
Also found in the metamorphic limestone, near 
slate (Fig. 49). In the upper peninsula of Mich¬ 
igan, on the shores of Lake Superior, which is the 
most celebrated locality for native copper, the rocks 
are sandstones and shales underlying greenstone or 
a kind of trap, and in some places seem to be igne¬ 
ous (Figs. 50 and 51). Ruby-copper ore occurs in 
Arizona between quartzose and hornblendic rocks 
and limestone. It occurs in both, lodes and de¬ 
posits, and the best way for the prospector to pre- 
12 


178 prospector’s field-book and guide. 

pare for actual discovery is to make himself well 
acquainted with the copper compounds, whether 
ores or minerals. They may indicate true ores, al¬ 
though they contain little copper. 

To become ready in the detection of copper as an 
ore, the following facts should be kept in mind, as 

Fio. 49. 


T> b 1) b 



Section of the copper bed at the Dolly Hide mine, Maryland, a . 
Slate. &, b , b , b . Ore beds or segregations of ore. c , c , c , c . Crystalline lime¬ 
stone (metamorphic). f 

furnishing suggestions for skilful practice. (Figs. 
49, 50 and 51.) 

It is well to remember, especially when exploring 
a new country, that copper is frequently associated 
with rocks of a dark color, which are very often 
green ; but it must not be supposed that the color 
is imparted by copper, for it is generally due either 
to some other metal, such as iron, or to the presence 
of a green non-metallic mineral, such as chlorite. 
Serpentine and hornblendic rocks are often asso- 









COPPER. 


179 


ciated.with copper ores, but green serpentines owe 
their color to iron, nickel or chromium, and if cop¬ 
per is found disseminated through some of them, it 
is the exception and not the rule, unless in the 


Fig. 50. 



Section of strata in Lake Superior copper region : a. Granite, b. 
Gneissoid. c. Greenstone, hornblende, conglomerates with interstratified 
slates, d. Slaty rocks and traps, etc. e. Potsdam sandstone. C, C. Places 
of copper deposits. 0, B. Iron ore beds. Section from N. W. to S. E. 


immediate vicinity of ore deposits. On the con¬ 
trary, iron and chromium are found in all serpen¬ 
tines, and nickel is of frequent occurrence. 

All copper ores weigh more than quartz or lime¬ 
stone, and the comparative weights should be so 


Fig. 51. 



Copper. Section of the Eagle vein, ,Lake Superior, a. Porphyritic 
rocks, b. Greenstone, c, c. Conglomerate, d, d, d. Amygdaloid bearing 
copper, e , e, e. Shafts. /. Montreal River. 


well known by practice that there should be no 
hesitation in judging that the mineral you hold is 
more than 2.6 in specific gravity, 2.6 being that 
of either quartz or limestone. 




















180 prospector’s field-book and guide. 

Next examine the mineral with your pocket lens 
for any evidence of copper, such as green or bluish 
spots, or brassy points or particles; if found, chip 
one off and use the blow-pipe with borax bead or 
with soda or borax on charcoal. If the character¬ 
istic color appears, it is copper. Now proceed with 
other parts of the specimen. If a sulphury smell is 
plain, it is probably a sulphide. Place a small chip 
upon a depression in the charcoal, cover with soda 
or borax, turn the inner flame upon it and reduce 
to a metallic globule ; if it shows the color of copper 
and is malleable, it is copper; if it blackens, apply 
your magnetized knife-blade, and if it is attracted, 
the mineral contains iron, and it may contain both 
iron and copper. 

The next work is to examine the region to gather 
any other specimens and evidences of true ores, 
before attempting to know more of any particular 
specimen. If the surface specimens are numerous 
it may be well to gather some six or eight, and pro¬ 
ceed to an examination as to the available copper. 
This is now the work of the chemist, and should be 
submitted to him. But as the skilled prospector 
frequently wishes to be his own chemist, where 
work for the desired object is not difficult nor very 
complicated, we give the following simple process 
of arriving at the per cent, of copper in an ore with¬ 
out regard to other elements contained therein : 

To OBTAIN THE PER CENT. OF COPPER IN AN ORE. 

The only chemicals needed are nitric acid, ammo¬ 
nia, and sodium sulphide—the colorless crystallized 


COPPER. 


18J 


bydrosulphide of soda of commerce is good enough. 
All the apparatus needed is a glass flask or tall 
beaker-glass and a marked tall glass called a burette. 
This glass may be obtained at any chemical ware¬ 
house. The burette is marked in cubic inches or 
cubic centimeters, from 25 to 100. Dissolve some 
sodium sulphide in clear rain-water—about a half 
ounce to a pint. Keep the solution in a glass- 
stoppered bottle. Obtain some pure copper (ordi¬ 
nary good copper wire will answer), weigh the piece 
accurately and dissolve in nitric acid, add some 
water (twice the amount of acid used, or a little 
more), then add ammonia until, when stirred with 
a long piece of glass or glass rod, the solution smells 
strongly of ammonia. The ammonia must be in 
excess. Now fill the burette with sodium sulphide 
to the 100-mark, and from the burette pour into 
the copper solution until the blue color of copper 
entirely disappears; note on the burette by its marks 
the exact amount of sodium sulphide used. That 
amount represents the weight of the amount of cop¬ 
per used. 

Now for the ore : Pulverize some of the averaged 
ore, weigh it, and treat it as you did the copper, 
with nitric acid and ammonia, and proceed with the 
sodium sulphide. When the ore solution has be¬ 
come entirely colorless, note what amount of sodium 
sulphide solution you have used, and you may then 
calculate the exact amount of copper in the ore by 
simple proportion. The presence of tin, zinc, lead, 
iron, cadmium, antimony, arsenic or bismuth in the 


182 prospector’s field-book and guide. 

ore does not interfere with the operation. But silver 
does. Therefore, a small amount of the ore must be 
dissolved in nitric acid (free from all muriatic acid 
or chlorine, as this would precipitate the silver be¬ 
fore you would notice it), and tested by dropping 
into the solution a drop or two of hydrochloric acid 
or solution of common table salt (sodium chloride). 
If any silver exists in the ore a milky cloudiness 
will appear, of a density greater or less in accord¬ 
ance with the amount of silver present. If no silver 
appears, then you may proceed as already directed. 
If silver does appear, then the solution containing 
the weighed ore must first be treated with the salt 
solution or diluted hydrochloric acid, until all cloudi¬ 
ness or white precipitate entirely ceases. The solu¬ 
tion of ore now contains no silver, and you may pro¬ 
ceed as directed. 

This process is sufficiently accurate for all assays, 
provided the following precautions are observed :— 

1. Heat the copper solution, after adding the am¬ 
monia, to boiling point or little below while adding 
the sodium sulphide. 2. Add a little ammonia to 
the ammoniacal solution to keep it from losing am¬ 
monia by evaporation. 3. When the blue am¬ 
moniacal solution begins to lose its color, drop the 
sodium sulphide in cautiously, so as not to exceed 
the amount necessary to exactly precipitate the 
copper and no more. 

Note the precipitates: The sodium sulphide first 
produces its black precipitate of copper sulphide, but 
before that takes place the ammonia will produce 


COPPER. 


183 


another precipitate, provided the copper contains 
any lead or tin. If the copper contains zinc, that 
will be precipitated immediately following the black 
copper sulphide, but will be white. If it contains 
any cadmium, that will be precipitated at the very 
moment the decoloration takes place, if the adding 
of the sodium sulphide is continued. Cadmium is 
known by a beautiful clear yellow precipitate. 
With care and skill each may be noticed. 

In simply determining the amount of copper, 
however, no regard need be had to any of these 
precipitates, only pay attention to the point of de¬ 
coloration. 

The sodium sulphide may need proving to see if 
it has lost any of its strength if kept for a long time, 
and this may be done by a trial with a new solution 
holding a known amount of copper. Or, exactly 
the same weight of crystals of sodium sulphide to 
the same amount of pure water may be used as be¬ 
fore, and the old solution thrown away. Or, by re¬ 
testing the sodium sulphide the same solution may 
be used for a long time, and if it has become weak¬ 
ened, make allowance for the additional sodium sul¬ 
phide required. It should be kept in a cool place, 
out of the sun and light also. 


CHAPTER IX. 


LEAD AND TIN. 

I. Lead. This mineral very rarely occurs native, 
and then only in small amounts. It has been found 
particularly in Sweden. Hardness, 1.5; specific 
gravity, 11.3 to 11.4. The most important ore of 
lead is the sulphide called 

Galena. When chemically pure it contains 86.6 
lead and 13.4 sulphur. Specific gravity, 7.2 to 7.5, 
according to admixtures. Color and streak, lead- 
gray. Luster, shining metallic ; the exposed surface 
may be dull from tarnish, but the fracture is bril¬ 
liant. Easily recognized by the characteristic cubi¬ 
cal cleavage, which is very easily obtained, or by 
the granular structure when massive. Frequently 
associated with other metallic sulphides, such as 
pyrite, chalcopyrite, arsenopyrite, blende, etc. It 
occurs in veins, thegangue of which is either quartz, 
calcite, barite or fluospar, in granite and nearly all 
varieties of rock, but the larger deposits are usually 
found either in veins or in pockets, often of great 
size, in limestone strata. It is also frequently found 
in gold-bearing lodes. 

Galena almost always contains silver and hence 
all galenas should be tested according to the process 
given on p. 161. It has been stated that galenas 
(184) 


lead and tin. 


185 


with small crystalline facets, like coarse lump sugar, 
are rich in silver, while those with large cleavages 
are poor ; but this character at the best is only local, 
for some galenas with large cleavages yield as much 
as 1,500 ozs. of silver per ton, whilst other fine¬ 
grained ores contains only 50 ozs. per ton, or even 
less. 

The order of strata in the galena district of Wis¬ 
consin, Illinois and Iowa is shown in the annexed* 
table. 


CAMBRO- 

SILURIAN 


NIAGARA LIMESTONE. 
f Galena limestone which bears lead. 

I Trenton limestone, fossils. 

Sandstones, shales, and calcareous beds. 
Lower magnesian limestones. 

Lower limit of lead. 


WHITE POTSDAM SANDSTONE. 

f Upper— 

j Fossiliferous slates. 
CAMBRIAN -{ Lower— 

j Dolomitic limestones. 

L Dark sandstones. 


Order of Strata in the Lead District of Wisconsin, Illinois and Iowa. 


The geology and form of lodes of the galena ores 
are seen in Fig. 52. 

Carbonate of Lead, White Lead Ore, or 
Cerussite. If perfectly pure its composition is, 
lead 83.6, carbonic acid 16.4. Hardness 3 to 3.5 ; 
specific gravity 6.4 to 6.5. Color (if freshly broken), 
white to gray, or even black, if it has been much 
weathered. Streak, colorless. Luster, glassy or 




186 prospector’s field-book and guide. 


adamantine; when pure is translucent, or even 
transparent. Very brittle. If it contains copper it 
is usually tinged blue or green. It has a glassy 
or vitreous appearance, and is easily melted before 
the blow-pipe, and a lead bead or globule is readily 
obtained. 

By using a little bone-ash plastered in a hollow 
in the charcoal and turning the 0. F. upon the lead, 

Fig. 52. 



after a little skilful blowing the lead is absorbed 
and drawn off and a bright silver globule remains, 
provided the lead contains silver. This is blowpipe 
cupelling. 

Carbonate of lead occurs in compact, earthy or 
fibrous masses, and is often found near the surface 
of a galena lode. At Leadville, Colorado, carbonate 
of lead has been found which contains 20 to 60 per 
cent, lead and 600 to 20,000 grapames of silver in a 
ton, the silver being present as chloride of silver 
(Fig. 53). 



LEAD AND TIN. 


187 


Sulphate of Lead or Anglesite often accom¬ 
panies the carbonate. It somewhat resembles the 
carbonate, although it is of slightly less hardness, 
2.75 to 3 ; specific gravity 6.12 to 6.3. Often in 
rhombic crystals. Luster, adamantine or glassy. 
Streak, white, gray or black. Fracture, conchoidal. 

Fig. 53. 


a 

b 

c 

d 

e 

e 


$ 


g 

Section of strata in California Gulch, Colorado, showing portion 
of the carbonate of lead deposits, a. Porphyritic rock, 12 to 100 ft. 
thick, b. Thin bed of white clay. c. Carbonate of lead bed, 1 to 20 ft. thick. 
d. Oxide of iron, 1 to 6 ft. thick, e, e. Limestone. /. Clay slates, g. Quartz¬ 
ites and metamorphic rocks resting upon gneiss. 



It may be distinguished from the carbonate by the 
fact that it does not effervesce in an acid, as the latter 
always will. It is composed of lead oxide 73.6 and 
sulphuric acid 26.4 in the pure specimens. 

Phosphate of Lead or Pyromorphite. Com¬ 
position, when pure, 89.7 phosphate and 10.3 
chromate of lead, with arsenate of lead (0 to 9), 


























188 prospector’s field-book and guide. 

phosphate of lime (0.11), and fluoride of calcium. 
Hardness, 3.5 to 4. Specific gravity, 6.5 to 7. 
Color, greenish, sometimes bright grass-green, the 
hexagonal crystals having a greasy luster, also yel¬ 
lowish, brownish, and sometimes dull violet. Lus¬ 
ter, resinous ; generally translucent. Streak, white 
or yellowish. Contains 78 per cent. lead. Heated 
on charcoal before the blow-pipe a globule is formed 
which takes on a crystalline appearance on cooling, 
leaving a yellow oxide of lead on the charcoal. 
With carbonate of soda in the reducing flame it 
yields a yellow globule. It is soluble in nitric acid. 

Crocoite or Chromate of Lead is a yellow 
mineral containing protoxide of lead 68.15, chromic 
acid 31.85. Hardness, 2.5 to 3 ; specific gravity, 5.9 
to 6.1. Color, various shades of bright hyacinth- 
red. Streak (powder) orange yellow. Luster, vitre¬ 
ous. Translucent, and sectile. Decrepitates before 
the blow-pipe. With soda on charcoal it yields a 
lead coating; with borax an emerald-green bead. 

Massicot or Lead Ochre. This mineral occurs 
massive, as a compact earth of a sulphury-yellow 
or reddish-yellow appearance. Hardness 2, specific 
gravity 8 and, when pure, 9.2. It is composed 
of oxygen 7.17, lead 92.83. Before the blow-pipe 
it fuses readily to a yellow glass, and on charcoal is 
easily reducible to metallic lead. 

Lead-Antimony Ores. There are several com¬ 
pounds of lead with antimony, but they are never 
sufficiently plentiful to be considered as ores. One 
of these, jamesonite, contains small proportions of 


LEAD AND TIN. 


189 


iron, copper, zinc and bismuth. It occurs in gray 
fibrous masses or small prisms, and is found in 
Cornwall, England, associated with quartz and 
bournonite. Another of these compounds, zinkenite, 
resembles stibnite and bournonite, and occurs in an 
antimony mine in the Hartz. 

The geology of lead. Almost all the galenas 
and the carbonates contain silver, and some of the 
latter, as in Colorado, contain large quantities of 
silver. The geology of lead is very much the same 
as that of silver. 

The ores are found in veins and lodes, and also 
in flats and beds, and in pockets (Fig. 54). The 
galenas occur in limestone, called the “ galena 
limestones,” a yellowish-gray, hard, compact crys¬ 
talline rock. The lowest horizon of lead ore in 
workable quantities lies above that of copper. 

“ The limestones and underlying schists are, for 
the most part, in a metamorphic condition, and 
there can be-no difficulty, from the presence of 
porphyry above and the quartzites and gneiss be¬ 
low, in recognizing their position,” * as in the 
Cambro-silurian system. It is supposed that the 
largest proportion of silver is contained in the ore 
derived from this geologic horizon. 

When water has had its course, however, the 
condition of a mine and of its veins and beds of 
ore may have been changed. Robert Hunt, as re¬ 
gards British mines, says that the circulation of 

* B. C. Davies, F. G. S. A Treatise on Metalliferous Minerals, 
London, 1892, p. 259. 


190 prospector’s field-book and guide. 

water in the veins is affected by the inclination of 
the strata in the direction of the vein. The richest 
deposits are found in that portion of strata which is 


Fig. 54. 



Section op Galena Limestone showing how the lead occurs in lodes, a, 
flats, b, b, b, and pockets, c, from mere threads to several feet in thickness. 


the most elevated, for instance, on the side of a 
powerful cross vein, Fig. 55, thus : 

The circulation of water is dependent upon an 
outlet at a lower level. 


Fig. 55. 



In the case of lead mines, it is stated that in 
consequence of the conditions connected with the 
descent of water, the richest deposits of lead are 






































LEAD AND TIN. 


101 


generally found at no great distance from the out¬ 
cropping of the containing rock. Veins which run 
on the sides of a mountain in a direction nearly 
parallel with the valleys contain more extensive de¬ 
posits of lead than those which cross the valleys at 
right angles.* 

The prospector should keep this suggestion in 
mind. 

The lead ores are found in the fissures where they 
seem to have been deposited by waters which have 
dissolved them out from neighboring beds (Fig 56). 

In the United States the chief sources of lead in 
late years have been argentiferous ores and consid¬ 
erable from zinc ores, but a notable exception is S. 
E. Missouri, where galena accompanied by nickel- 
iferous pyrite is disseminated through magnesian 
limestone of Cambrian age. The mines are at 
Bonne Terre, Mine la Motte and Doe Run. The 
strata lie almost horizontal, and are known to carry 
lead through over 300 feet in thickness. 

II. Tin. When a tin-bearing mineral is heated 
before a blow-pipe with carbonate of soda or char¬ 
coal, white metallic tin is yielded. By dissolving 
this in hydrochloric acid and adding metallic zinc, 
the tin will be deposited in a spongy form. In the 
blow-pipe assay tin leaves behind a white deposit 
which cannot he driven off in either flame. If it 
be moistened with nitrate of cobalt solution, the 
deposit becomes bluish-green, and this test distin¬ 
guishes it from other metals. 

* British Mining, by s Robert Hunt, London, 1884, p. 344. 


192 prospector’s field-book and guide. 

Assay of tin ore. If the ore is poor it should be 
concentrated, the vein-stuff being got rid of as much 
as possible. If mixed with iron or copper pyrites, 
it should be calcined or else treated with acids. 
One method is to mix the ore with one-fifth of its 
weight of anthracite coal or charcoal, and expose it 
in a crucible to a great heat for about twenty min¬ 
utes. The contents are then poured out into an 
iron mould, and the slag carefully examined for 
buttons. 


Fig. 56. 



Section of a Lead Deposit in a Fissure of the Limestone. Williams & 
Co.’s Mine, Wisconsin. B , B , B , B , limestone. A , the fissure running down, 
C , C , C , C , masses of ore. Metamorphic. 

Another method is to mix 100 grains of the ore 
with six times its weight of cyanide of potassium, 
and expose the mixture to the heat of a good fire 
for twenty minutes. The contents are allowed to 
cool and afterwards broken to remove the slag. 

Cassiterite or Tin Stone. This mineral forms 
the principal source of tin, and when pure contains 
78.6 per cent, of metallic tin. It is remarkable for 
its hardness (6 to 7), and still more so for its specific 
























LEAD AND TIN. 


193 


gravity (6.8 to 7). It contains small quantities 
of iron, copper, manganese, tungsten, tantalic acid, 
arsenic, sometimes silica, and rarely lime. It is 
found associated with quartz, mica, topaz, tourma¬ 
line, wolfram, chlorite, iron, copper, and arsenical 
pyrites. It occurs massive and in crystals, also in 
botryoidal and reniform shapes, concentric in struc¬ 
ture and radiated fibrous, and is then in the last 
form called wood tin, from its woody appearance. 
Toad-eye tin is the last described, but in very small 
shot-like grains. Stream tin is nothing but the ore 
in a state of sand as it occurs along the beds of the 
stream or the gravel of the adjoining region. It 
has been derived from tin veins or rocks. 

Cassiterite yields a white, grayish, or brownish 
streak ; has a brownish color and a dull luster. It 
is nearly as hard as quartz, and will scratch glass, 
especially if freshly broken. Pure crystals are rare. 
They are nearly transparent, but in the mass, as it 
occurs in the mines in Dakota and in many other 
places, the ore is of a dark brown color, and some¬ 
times almost black ; the fine powder or streak as 
made by a file, is light brown, however dark the 
mineral may be. The brown color or shade is due 
to oxide of iron in composition; if perfectly free 
from all associated impurities it would be nearly 
white or colorless. The usual appearance in mass 
or pebbles, or finer, is that of a dirty or burned- 
brown color with varying depths of shade. 

In the pebble form it is apt to wear quite smQoth, 
due to its extreme hardness. 

13 


194 prospector’s field-book and guide. 

It was in this form that it was discovered in 
JBanca, in 1710, and in the neighboring island, 
Billiton, and traced to its source in the mountains, 
where the central rock is granite, covered by quartz¬ 
ites, altered sandstones, and slaty rock. The 
altered sandstone just above the granite is the most 
productive rock, and it is traversed in all directions 
with tourmaline. * The same general associations 
largely exist in Wyoming and Dakota tin mines. 

There is another mineral containing tin which 
may lead to the discovery of the true ore. It re¬ 
quires only a short description, which is given below: 

Tin pyrite (sulphide of tin), whose composition is, 
as a mineral, 29 to 30 sulphur, 25 to 31 tin, 29 to 
30 copper, with iron and sometimes zinc. It has 
been dug as an o*re of copper and called “ bell- 
metal.” Its hardness is 4 ; specific gravity 4.3 to 
4.5 ; has a metallic luster; color, steel-gray to black, 
often yellowish from the presence of copper sul¬ 
phide ; it is opaque and brittle. 

With nitric acid it affords a blue solution, and 
sulphur and tin oxide separate and may be tested 
on charcoal, where it fuses to a globule, which, in 
the oxidizing flame, gives off sulphur and coats the 
coal with white oxide of tin. 

This ore or mineral, for it does not as yet deserve 
the name of tin ore, is of little use, but the pros¬ 
pector does well to make himself acquainted with it, 
as it is frequently associated with the binoxide or 

* D. C. Davies, F, G, S,, Metalliferous Minerals, London, 1892, 
p. 194, 


LEAD AND TIN. 


195 


cassiterite, or black oxide, as the true ore is fre¬ 
quently called. 

In the United States, cassiterite occurs in small 
stringers and veins on the borders of granite knobs 
or bosses, either in the granite itself or in the adja¬ 
cent rocks, in such relations that it is doubtless the 
result of fumarole action consequent on the intru¬ 
sion of the granite. It appears that the tin oxide 
has probably been formed from the fluoride. The 
Cajalco mine in California and the Harvey Peak 
mines, South Dakota, have been developed, but it is 
questionable whether they are worked at a profit. 
Undeveloped deposits are reported in Alabama, 
North Carolina and Virginia. At Broad Arrow, 
near Ashland, Alabama, tin-ore is disseminated in 
gneiss, the ore averaging about If per cent, black 
tin, but being very much mixed with titaniferous 
iron. At King’s Mountain, North Carolina, cassi¬ 
terite occurs very irregularly in a “greisen” or 
altered granite, and in limited alluvials derived 
from the disintegration of the same. On Irish 
Creek,‘Virginia, experimental parcels of vein-stone 
taken from deposits in granite have shown 3J to 3f 
per cent, metallic tin, largely associated with arsen¬ 
ical pyrites and ilmenite, which increase the diffi¬ 
culties of concentration and lower the value of the 
product. 

On the Seward Peninsula, Alaska, stream tin 
(cassiterite) has been found on Buhner C^eek and 
on the Anikovik River, by the miners in the sluice- 
boxes. On Buhner Creek 2 to 3 feet of gravel 


196 prospector’s field-book and guide. 

overlies the bed rock, which consists of arinaceous 
schists, often graphitic, together with some graphitic 
slates. The bed rock is much jointed, the schists 
being broken up into pencil-shaped fragments. 
They strike nearly at right angles to the course 
of the stream and offer natural riffles for the con¬ 
centration of heavier material. The slates and 
schists are everywhere penetrated by small veins, 
consisting usually of quartz with some calcite, and 
frequently carrying pyrite and sometimes gold. 
These veins are very irregular, often widening out 
to form blebs, and again contracting so as not to be 
easily traceable. The cassiterite occurs in grains 
and pebbles, from those microscopic in size to those 
half an inch in diameter, and varies in color from 
a light brown to a lustrous black. The production 
of tin in Alaska in 1907 to 1908 amounted to 
$ 20 , 000 . 

Deposits of tin occur at El Paso, Texas. The 
ores consist of cassiterite, with wolframite (tungstate 
of iron and manganese) in a gangue of quartz. 
Specimens of nearly pure cassiterite weighing sev¬ 
eral pounds have been found on the surface, and 
this mineral occurs in the quartz, either alone or 
associated with wolframite. The most abundant 
ore is a granular mixture of tin ore with quartz 
which resembles a coarse granite and corresponds 
to the greisen ore of European deposits. These 
ores occur in well-defined veins, which run up the 
slopes nearly at right angles to the direction of the 
range. These veins exhibit the usual character- 


LEAD AND TIN. 


197 


istics of the European tin veins, their clearly defined 
fissures showing a central core of lead of coarse 
quartz, sometimes containing tin ore, and flanked 
on either side by altered rock in which the tin ore 
replaces the feldspar of the granite. 

Cassiterite stands nearly by itself in its mode 
of occurrence and formation, as a type of a strongly 
marked class of deposits. It is always associated 
with granitic rocks, quartz-porphyries, or gneiss, all 
of which are of analogous composition, being rich 
in silica, which crystallizes as quartz, and being 
called in consequence “ acidic ” rocks. Tin lodes 
are nearly all of great antiquity and occur only in 
those of the above-named rocks which are charac¬ 
terized by the presence of white mica. It is only 
in two or three places in the world, notably Tus¬ 
cany and Elba, that granites of this type have been 
erupted during recent times, and they contain tin 
in small quantity as well as some of the minerals 
usually associated with it, such as tourmaline, 
lithia, mica, and emerald. 

Although this fact is of no immediate practical 
value, it is important, because it shows that there 
really are laws which govern the distribution of 
minerals, although these are sometimes very ob¬ 
scure ; but by constant observation it is certain that, 
amongst discoveries of merely scientific interest, 
laws capable of practical application will occasion¬ 
ally be found. 

Cassiterite is always associated wfith quartz and 
rarely occurs in green rocks, unless their color be 


198 prospector’s field-book and guide. 

due to chlorite ; nor in dark-colored rocks, except 
where stained red by the decomposition of ferru¬ 
ginous minerals ; neither is it found in limestone. 

Those granites which are characterized by abund¬ 
ance of white mica have, with good reason, been 
termed “ tin granites,” and a coarse-grained rock 
composed of granular quartz mixed with white mica 
and called “greisen” occurs in all the tin fields of 
the world. 

The minerals most commonly associated with tin, 
namely topaz, mica, tourmaline, fluorspar, apatite 
and other rarer minerals containing fluorine, seem 
to show that it was originally contained in the 
granite as fluoride of tin, and that the associated 
minerals have been formed at its expense. It is an 
established fact in the genesis of minerals that fluor¬ 
ine is always accompanied by silicon and boron. 
It is therefore natural to find silicates containing 
boric acid, such as tourmaline and axinite, in asso¬ 
ciation with tin. Other minerals which frequently 
accompany this metal are wolfram, molybdenite, 
mispickel, garnet, beryl, etc. 

It is evident that a most important aid to the 
prospector is a study of the characteristics of the 
tinstone ores, and he may find it beneficial to be¬ 
come acquainted with the special minerals above 
mentioned as associated with the ores. 

These minerals include, in some mines, wolframite , 
which gives trouble in the Cornwall and other tin 
mines, and the following description and tests may 
aid in detecting it: 


LEAD AND TIN. 


199 


Wolframite is in hardness 5 to 5.5, specific gravity 
7.1 to 7.55, therefore, in these features it resembles 
the tin oxide; though somewhat softer, yet the spe¬ 
cific gravity is practically the same, although really 
heavier. So in color it frequently closely resembles 
tin oxide. But in the streak (or scratch powder), 
wolframite is a dark reddish-brown to black, while 
the tin oxide gives a white or grayish-brown pow¬ 
der ; wolframite is opaque, while the tin oxide is 
translucent and sometimes transparent on the edges ; 
when mixed with iron or manganese rarely, it looks 
almost opaque. Composition of wolframite : Tung¬ 
stic acid about 75, the remainder protoxide of iron 
and manganese protoxide, more of the latter than 
of the former. 

Wolframite is used in the preparation of some 
colors and enamels, and enters into the composition 
of some special kind of steel. Tungstate of soda, 
which is used as a mordant and for fire-proofing 
fabrics, is also prepared from it. 


CHAPTER X. 


ZINC, IRON, MOLYBDENUM, TITANIUM, URANIUM, 
VANADIUM. 

I. Zinc. Zinc is never found free in nature, but 
chiefly occurs in combination with carbonic acid 
and united with sulphur. The chief ores are : 

Smithsonite or Zinc Carbonate. Composition, 
zinc 51.44, oxygen 13.10, carbonic acid 35.46. 
But the composition in the mines varies because 
of the presence of protoxide of iron, manganese and 
magnesia. Color, when pure, nearly white, through 
various shades of yellow and gray to brown. Hard¬ 
ness 5, specific gravity 4 to 4.4. Streak, uncolored 
or white. Luster, vitreous, pearly, subtransparent 
to translucent. Found -in veins, but more usually 
in irregular deposits in limestone strata. 

It is easily detected by the blow-pipe, as it gives 
a green color when heated after being moistened 
with half a drop of nitrate of cobalt solution. On 
charcoal, with soda, it coats the charcoal with a 
white film, which is yellow when hot and white on 
cooling, but if moistened with the cobalt solution 
and heated in the 0 F turns green. With muri¬ 
atic acid it effervesces and dissolves. In mass it is 
translucent and brittle. 

( 200 ) 


ZINC, IRON, MOLYBDENUM, TITANIUM. 201 

Calamine. This is a silicate of zinc. Composi¬ 
tion, zinc oxide 67.5, silica 25, water 7.5. Hard¬ 
ness 4.5 to 5, the latter when crystallized (Dana); 
specific gravity 3.16 to 3.9. Color when pure, pearl} 7 
white, but owing to the presence of iron oxide, 
etc., generally brownish, sometimes green. Streak, 
whitish. Luster, pearly or glassy. Acts before the 
blow-pipe like Smithsonite, but does not effervesce 
with acids, and gelatinizes; it is soluble in a strong 
solution of potash. In physical characters zinc 
silicate somewhat resembles zinc carbonate. An 
anhydrous variety of this ore is Willemite, which is 
found in New Jersey (Mine Hill and Sterling Hill). 
Zinc silicate is usually found in veins or in beds or 
in irregular pockets in stratified calcareous rocks, 
in association with zinc blende, zinc carbonate, iron, 
lead ores, etc. 

Zincite or red oxide of zinc. Its composition 
is zinc 80, oxygen 20, varied by the presence of 3 to 
12 parts of peroxide of manganese, which gives the 
red color, for zinc oxide, pure, is white. Hardness 
4 to 4.5 ; specific gravity 5.4 to 5.7 ; color, red and 
yellowish-red, streak the same; luster, brilliant; 
translucent, brittle. Occurs in grains or masses. 
Is found chiefly in Sussex Co., New Jersey. 

Sulphide of zinc, sphalerite or zinc blende. 
Miners’ names, black jack, false lead, false galena. 
Composition, zinc 66.8, sulphur 33.2, but varied in 
the mines by iron, and sometimes cadmium. Color 
varies from yellow to brown and almost black, hav¬ 
ing a waxy look. Streak, white to reddish-brown. 


202 prospector's field-book and guide. 

Luster, waxy. Hardness 3.5 to 4 ; specific gravity 
3.9 to 4.2 ; brittle, translucent. Zinc blende is the 
most abundant zinc ore. It occurs in rocks of all 
ages, in veins, in contact deposits or in irregular 
pockets in limestone, etc., and is frequently associ¬ 
ated with the ores of lead, as well as those of copper, 
iron, silver, gold and tin ; also, frequently associ¬ 
ated with quartz, barite, fluorite, calcite, etc. It is 
easily recognized if treated with hot hydrochloric 
acid, as it gives a smell of rotten eggs (sulphuretted 
hydrogen), and the same results can be obtained with¬ 
out heating if a small quantity of pure iron filings 
is added to the acid. With soda on charcoal before 


Fig. 57. 



Section of strata near Sparta, New Jersey, zinc mines. 
a, Slaty rock with feldspathic dykes, b, b, Limestone, c, Franklinite iron 
ore with zinc, 20 to 30 ft. wide, d, Red oxide of zinc, 3 to 9 ft. wide, e, e , 
Crystalline limestone. /, Feldspathic rock. 

the blow-pipe, zinc blende gives a sulphuret which, 
with water on a silver coin, tarnishes or blackens it. 

The geology of zinc and that of lead are so nearly 
alike that what has been said of the latter will apply 
to the former (Fig. 57). 

In New Jersey a section of strata near Sparta, 







ZINC, IRON, MOLYBDENUM, TITANIUM. 203 

Sussex Co., shows slaty rock with feldspathic dykes, 
then limestone adjoining the Franklinite iron ore 
with zinc 20 to 30 feet wide, then the red oxide of 
zinc 3 to 9 feet wide, then crystalline limestone, and 
next feldspathic rock (Fig. 57). 

Enormous and extensive deposits of the sulphide 
are reported as occurring in Colorado, at George¬ 
town and Mount Lincoln, and in Montana, near 
Jefferson City. 

The blow-pipe shows the same tests for zinc as 
have previously been mentioned. The fumes of 
sulphurous acid may be easily noticed when the 
mineral is placed in an open tube of glass (a test- 
tube with a small hole in the bottom will be suffi¬ 
cient), and is strongly heated. 

II. Iron. This metal is one of the most abund¬ 
ant and widely distributed elements of the earth’s 
crust, its distribution being materially aided by the 
fact of its forming two oxides of different chemical 
quantivalence. Native iron, or iron in the metallic 
state, is very rarely found in nature, it occurring 
almost entirely in meteoric iron. 

Native or Meteoric Iron. Occurs in small 
grains in the platinum-carrying sand of Siberia and 
in larger coherent masses in rocks in Canada. How¬ 
ever, of greater interest is the occurrence of native 
iron in meteorites which occasionally fall to the earth. 
As a rule they do not exceed a few pounds in weight, 
and only a few weighing more than 220 lbs. have 
thus far been discovered. . In 1870, large masses 
weighing from 10,000 to 50,000 lbs. were discovered 


204 prospector’s field-book and guide. 

imbedded in basalt at Disko, Greenland. Several 
meteoric masses containing small black diamonds 
have been found in Arizona. Meteorites are dis¬ 
tinguished by the fact that they contain nickel and 
traces of cobalt, copper and other metals. In fact, 
the presence of nickel is the criterion for the gen¬ 
uineness of a meteorite. Actual meteoric iron in 
which the presence of nickel could not be estab¬ 
lished has thus far been found only at Scriba 
and in Walker County, Alabama. In specimens 
of meteorites examined, the iron ranges from 67 to 
94 per cent, and the nickel from 6 to 24. Below 
some analyses of meteoric iron found in this country 
are given : 



From 
Hominy 
Creek, North 
Carolina. 

From Bur¬ 
lington, 
New York. 

From 
Babb’s 
Mill, Ten¬ 
nessee. 

From 

Claiborne, 

Alabama. 

Iron . ... 

93.225 

89.752 

80.594 

88.04 

Nickel .... I 

0.236 | 

8.897 

17.104 

10.73 

Cobalt . . J 

0.625 

2.037 

0.46 

Manganese . . . 

— 

— 

— 

0.13 

Copper. 

— 

— 

— 

— 

Tin. 

0.099 

— 

— 

0.07 

Sulphur .... 

0.543 

— 

— 

— 

Phosphor-nickel- 
iron . 


0.703 

0.124 


Silicon. 

0.501 

— 

— 

— 

Carbon. 

4.765 

— 

— 

— 


Meteorites may be distinguished from metallic 
iron of other origin by peculiar markings which 
are produced when the surface is polished and 

















ZINC, IRON, MOLYBDENUM, TITANIUM. 205 

treated with nitric acid. These markings are due 
to combinations of iron with nickel, and partly also 
with phosphorus, which are not decomposed, or 
only with difficulty by acids, and are imbedded in 
a crystalline state in the remaining mass of iron, 
the latter being quickly dissolved by the acid, while 
the former are not attacked for a long time. 

The most important ores of iron are: 

Magnetite or magnetic iron ore is found in 
octahedral or decahedral crystals; more commonly 
simply massive. Streak, black; color, black. Com¬ 
position, iron 72.4, oxygen 27.6. Hardness, 5.5 to 
6.5 ; specific gravity, 5 to 5.1. The ore is always 
easily attracted by the magnet, and sometimes is 
found capable of attracting iron, and is then called 
polaric or loadstone. In powder or small grains it 
is always attractable by a magnetized knifeblade. 

The usual geological position of magnetite is in 
the most highly metamorphic rocks, in which it 
probably represents the excess of iron oxide origi¬ 
nally in the rock which was not taken up by silica. 
Occasionally it is found in layers, but in this 
country and elsewhere it forms whole mountains. 
Among other rocks in which it occurs the following 
are the most important: Crystalline limestone, 
chloritic, talcose, hornblendic, pyroxenic and hy¬ 
persthenic schists; serpentine, diorite and basalt. 
Specular iron is frequently associated with it. 

Magnetite is not acted upon by nitric acid, but 
hydrochloric acid dissolves it when in very fine 
powder and under long-continued heat. 


206 prospector’s field-book and guide. 

Iron exists in magnetite as protoxide and per¬ 
oxide, or FeO and Fe 2 0 3 , and upon this difference 
of oxides is based the action of important tests. 

Franklinite is an ore somewhat resembling 
magnetite in color, hardness, and specific gravity, 
but it contains manganese and zinc, and as an ore, 
is peculiar to Sussex Co., New Jersey. Color, dark 
black. Streak, dark brown. Its action on the 
magnet is feebler than in the case of magnetite. 
The iron is said to be of the composition of per¬ 
oxide, or Fe 2 0 3 , but it is probably in part protoxide, 
and this is the cause of its feeble effect on the 
magnet. 

It is easily affected under the blow-pipe. Alone, 
it is infusible, but with borax in the 0 F it colors 
the borax bead with the amethystine color of man¬ 
ganese, and in the R F it shows the bottle-green of 
iron. On charcoal with soda it gives the bluish- 
white manganate, and also the coating of zinc, 
especially if the soda is mixed with borax. In fine 
powder soluble in hydrochloric acid. 

Specular ore is the peroxide of iron without the 
protoxide. This oxide is also called the sesqui- 
oxide, or one and a half oxide, since iron combines 
with oxygen in the proportion of one to one and a 
half parts, or Fe 2 0 3 , and this is the highest propor¬ 
tion of oxygen the iron will combine with, and 
hence it is the peroxide, the peroxide and sesqui- 
oxide being the same in this case. 

Specular ore is called red hematite from its 
color, w T hich in some masses is so intensely red as to 


ZINC, IRON, MOLYBDENUM, TITANIUM. 207 

appear nearly black, but it may always be distin¬ 
guished from magnetite by its red streak, and the 
blacker the ore the more decided is the red of its 
powder or streak. It is never magnetic. It has 
been found that in cases where specular ore showed 
any magnetic attraction, it was due to the fact that 
the ore contained some protoxide of iron. 

Hardness 5.5 ; specific gravity 4.5 to 5.3 ; com¬ 
position 70 per cent, iron, 30 per cent, oxygen. 
Color, reddish to almost black. Streak, red. Lus¬ 
ter, metallic, but dull and earthy in some varieties. 

Brown Iron Ore or Brown Hematite or 
Limonite. This is the same composition as red 
hematite, except that it has less iron and contains 
water in chemical combination, generally about 14 
per cent. Color, brown, yellow and coffee color. 
Streak, yellowish. Luster, dull or submetallic. 
Hardness 5 to 5.5; specific gravity 3.6 to 4. When 
heated red-hot it loses its water and turns to a 
bright red, unless largely mixed with alumina and 
silex, when the red color is shaded. It is not mag¬ 
netic unless heated with soda under the blow-pipe, 
when it becomes metallic, as all iron ores do. 

The amount of metallic iron in a pure specimen 
is 59 per cent., sometimes decreased by the presence 
of alumina, silica, magnesia, and other impurities, 
so that its average in many good mines is only 
about 35 to 36 per cent. iron. 

Spathic iron ore or siderite is an iron carbon¬ 
ate, composed of iron protoxide 62 per cent, and 
carbonic acid, or 48 per cent, pure iron. Sometimes 


208 prospector’s field-book and guide. 

massive, with a crystalline structure. Hardness, 
3.5 to 4.5; gravity, 3.7 to 3.9; streak, white. 
Color gray or cream color, unless weathered, when 
it is brownish. Luster glassy or pearly. 

When in powder it effervesces with muriatic acid, 
especially when hot. Translucent on edges, and 
thin plates or splinters. 

With the blow-pipe in a closed tube (test-tube) it 
decrepitates, becomes blakened, and gives off car¬ 
bonic acid. Before the blow-pipe alone, held by 
forceps, it blackens and fuses. In the test-tube with 
muriatic acid it may be tested for carbonic acid, by 
letting a lighted thread down into the tube, when 
the flame is instantly extinguished. The solution 
in the tube may be tested for iron by dropping a 
drop of solution of ferricyanide of potassium into the 
muriatic acid solution, when it becomes instantly a 
deep blue. This is a test of protoxide of iron, 
spathic ore being iron in the condition of protoxide 
only. 

Black band ore is an argillaceous spathic ore of 
various dark colors, being largely combined with 
carbonaceous material. It is found extensively in 
Great Britain, near the summit of the coal measures. 
In our country the black band ores are also associ¬ 
ated with the coal measures, both in the anthracite 
and bituminous regions. 

Chromic Iron or Chromite, generally with 49.90 
to 60.04 per cent, of chromic oxide, 18.42 to 35.68 
per cent, of ferrous oxide, 10 to 12 per cent, alumina, 
5.36 to 15 per cent, magnesia, and 4 to 6 per cent. 


ZINC, IRON, MOLYBDENUM, TITANIUM. 209 

silica, occurs usually massive, mixed with other iron 
ores or in serpentine. Color, black to brownish- 
black. Luster faintly metallic. Streak or powder, 
dark-brown. Fracture, irregular ; specific gravity, 
4.4 to 4.6 ; hardness, 5.5, is not scratched by a 
knife. With borax bead it gives the characteristic 
indications of chromium. It is largely used in the 
preparation of chromium colors. 

The following iron ores are not used for the mak¬ 
ing of iron and steel, but may nevertheless prove of 
value. 

Iron Pyrites, usually in cubes and allied forms, 
sides often marked by fine parallel lines. Occurs 
also massive and contains 46.7 per cent, of iron and 
53.3 per cent, of sulphur. Color, brass yellow; 
luster, metallic; streak, brownish-black; fracture 
irregular ; specific gravity. 4.8 to 5.1 ; hardness, 6 to 
6.5; cannot be scratched with a knife, but is 
scratched by quartz, and scratches glass with great 
facility. Before the blow-pipe it burns with a blue 
flame, giving off an odor of sulphur, and ultimately 
fuses into a black magnetic globule. It is found in 
great abundance, and is used as a source of sulphur. 
It is easily distinguished from copper pyrites by its 
hardness, the latter being readily cut with a knife. 
From gold it is distinguished by its hardness and in 
not being malleable, and in giving off sulphurous 
odors in the blow-pipe flame. 

Arsenical Pyrites or mispickel contains 34.4 
per cent, of iron, 19.6 per cent, of arsenic, and 46.0 
per cent of sulphur. It occurs in flattened prisms 
14 


210 prospector’s field-book and guide. 

and also massive. Color, white ; luster, metallic ; 
streak, gray ; fracture, uneven ; specific gravity, 6.0 
to 6.3 ; hardness, 5.5 ; cannot be scratched with a 
knife, but is scratched by quartz. Heated before 
the blow-pipe, it gives off white arsenical fumes of a 
garlic odor, and finally fuses into a black globule. 
It is abundant in mining districts, and sometimes is 
auriferous. With the improved processes now in 


Fig. 58. 



Geologial Horizons around the Iron Ores of Lake Superior. 
a. Gneiss. 6. Hornblende slates, c. The same with numerous thin beds 
of iron ore which frequently unite, d. Potsdam sandstone. 

use, it is possible to extract the gold profitably, and 
hence mispickel ores should be examined for gold. 

The Geology of the iron ores varies, and may be 
divided into that of the magnetites, which are al¬ 
ways derived from the granite, gneiss, schist rocks, 
clay slates, and, rarely, the metamorphic limestones, 




ZTNC, IRON, MOLYBDENUM, TITANIUM. 211 


The red hematites seem to be only an alteration 
derived from the magnetites, and belong to the 
same more ancient rocks as the latter. 

The brown hematites (limonites) are derived from 
both the former, and are generally sedimentary. 

Very frequently in extensive magnetic regions, 
where the country back is mountainous, the brown 
ore has been formed in basins and knees and inter¬ 
locked portions of the lower country, where ages of 
rains, storms and freshets have gradually trans- 


Fig- 59- 



Section of Pilot Knob, Missouri. 


a . Quartzite or siliceous rock, b• Red hematite iron ore alternating with 
siliceous matter, c■ Siliceous rocks. 


ported and altered the magnetic ores of the upper 
regions and brought down these iron oxides to the 
low lands, where they have been arrested and set¬ 
tled down in beds of brown hematite. This seems 
to have been the history of all the hematitic limonite 
beds and deposits; they are on the lower levels 
when they were formed, although in after ages they 
may have been uplifted. 




212 prospector’s field-book and guide. 

Iron ores are, therefore, to be found in three gen¬ 
eral geologic regions: (1) in the earliest rocks ; (2) 
in the carboniferous, and (3) in the more recent or 
sedimentary rocks, and in accordance with their 
composition as magnetites and specular ores, as 
carbonacous or black band and spathic ores, or as 
brown ores of the limonite order. 

One of the most peculiar geologic condition is 
found in the Pilot Knob Mountain, wherein the 
iron strata have been thrown up as in Fig. 59. 

THE USE OF THE MAGNETIC NEEDLE IN PROSPECTING 
FOR IRON. 

In ordinary cases, where the surface is covered 
with loose earth, it is common to search for mag¬ 
netic iron ore with a magnetic needle or a miner’s 
compass, and for preliminary examinations it is 
now the chief reliance. In using this instrument 
considerable practice is required ; but this joined to 
good judgment gives indications of the presence of 
ore which are almost infallible. There has been 
very great improvement, within a few years past, in 
the methods of searching for magnetic ore as well 
as in the instruments to be used for that purpose, 
and the work is now well done by many persons. 

In the Annual Report of the State Geologist of 
New Jersey for 1879, W. H. Scranton, M. E., makes 
a report, accompanied by a map, upon a magnetic 
survey made at Oxford, Warren Co., New Jersey, to 
determine the location of a vein, and the proper 
places to sink shafts. Mr. Scranton finds Gurley’s 


ZINC, IRON, MOLYBDENUM, TITANIUM. 213 

Norwegian compass the best, though the slowest to 
work with. He sums up the indications from the 
magnetic needle in searching for ore, as it usually 
occurs in New Jersey, as follows: 

“ An attraction which is confined to a very small 
spot and is lost in passing a few feet from it, is most 
likely to be caused by a boulder of ore or particles 
of magnetite in the rock. 

“An attraction which continues on steadily in the 
direction of the strike of the rock for a distance of 
many feet or rods, indicates a vein of ore; and if it 
is positive and strongest towards the southwest, it is 
reasonable to conclude that the vein begins with the 
attraction there. If the attraction diminishes in 
going northeast, and finally dies out without becom¬ 
ing negative, it indicates that the vein has con¬ 
tinued on without break or ending until too far off 
to move the compass needle. If, on passing towards 
the northeast, along the line of attraction, the south 
pole is drawn down, it indicates the end of the vein 
or an offset. If, on continuing further still in the 
same direction, positive attraction is found, it shows 
that the vein is not ended ; but if no attraction is 
shown, there is no indication as to the further con¬ 
tinuance of the ore. 

“ In crossing veins of ore from southeast to north¬ 
west, when the dip of the rock and ore is as usual to 
thejsoutheast, positive attraction is first observed to 
come on gradually, as the ore is nearer and nearer 
to the surface, and the northwest edge of the vein is 
indicated by the needle suddenly showing negative 


214 - prospector’s field-book and guide. 

attraction just at the point of passing off it. This 
change of attraction will be less marked as the 
depth of the vein is greater, or as the strike is nearer 
north and south. The steadiness and continuance 
of the attraction is a much better indication of ore 
than the strength or amount of attraction is* The 
ore may vary in its susceptibility to the magnetic 
influence from impurities in its substance ; it does 
vary according to the position in which it lies— 
that is, according to its dip and strike ; and it also 
varies very much according to its distance beneath 
the surface. 

“ Method of Using the Compass in Searching for Ore. 
—It is sufficient to say that the first examinations 
are made by passing over the ground with the com¬ 
pass in a northwest and southeast direction, at in¬ 
tervals of a few rods, until indications of ore are 
found. Then the ground should be examined more 
carefully by crossing the line of attraction at inter¬ 
vals of a few feet, and marking the points upon 
which observations have been made, and recording 
the amount of attraction. Observations with the 
ordinary compass should be made and the varia¬ 
tion of the horizontal needle be noted. In this way 
material may soon be accumulated for staking out 
the line of attraction, or for constructing a map for 
study and reference. 

“ After sufficient exploration with the magnetic 
needle, it still remains to prove the value of the 
vein by uncovering the ore, examining its quality, 
measuring the size of the vein, and estimating the 


ZINC, IRON, MOLYBDENUM, TITANIUM. 215 

cost of mining and marketing it. Uncovering 
should first be done in trenches dug across the 
line of attraction, and carried quite down to the 
rock. When the ore is in this way proved to he of 
value, regular mining operations may begin. 

“In places where there are offsets in the ore, or 
where it has been subject to bends, folds, or other 
irregularities, so that the miner is at fault in what 
direction to proceed, explorations may be made with 
the diamond drill.” 

Molybdenum. The sulphide occurs native as 
Molybdenite in crystallolaminar masses or tabular 
crystals, having a strong metallic luster and lead- 
gray color, and forming a greenish-black streak 
which is best seen by drawing a piece across a china 
plate. Specific gravity, 4.5 to 4.6 ; hardness, 1 to 
1.5 ; easily scratched by the nail. It contains 58.9 
of molybdenum and 51.1 per cent, of sulphur. It 
occurs sparingly in granite, syenite and chlorite 
schists, and is sometimes mistaken for graphite, from 
which it is, however, readily distinguished by the 
streak, that of graphite being black. Before the 
blow-pipe it is infusible, but tinges the flame faint 
green. Heated on charcoal for a long time it gives 
off a faint sulphurous odor and becomes encrusted 
white. Its chief use is in the preparation of a blue 
color. 

IV. Titanium occurs in nature in the form of 
titanic oxide. The most important minerals con¬ 
taining titanium are : 

Rutile. This mineral resembles cassiterite, but 


216 prospector’s field-book and guide. 

has a lower specific gravity, is red by transmitted 
light, and crystals are more prismatic. It occurs in 
striated prisms, many times twinned ; in eight-sided 
prisms with flat pyramidal termination, rarely com¬ 
pact massive. Hardness, 6 to 6.5. Specific gravity, 
4.2 to 4.3. Color, reddish brown to black, by trans¬ 
mitted light deep red. Streak, yellowish brown. 
Luster, adamantine. Occurs in granite, gneiss, 
syenite, mica schist, and granular lime-stone. It 
generally contains enough iron to give a reaction in 
the borax bead. With salt of phosphorus in R. F. 
the strongly saturated bead is purplish violet. It 
is used for preparing some enamels and when pure 
for coloring artificial teeth. 

Octahedrite , occurs in elongated octahedrons some¬ 
times so splendent as to be mistaken for diamonds. 
Black or brown, yellow, sometimes fine blue. Re¬ 
actions same as for rutile. 

Brookite. Brown to black, crystals often tabular, 
generally distinctly orthorhombic, always readily 
distinguished from tetragonal. Reactions same as 
for rutile. 

The mode of occurrence of the last two minerals 
is frequently the same as rutile, and they, like 
rutile, frequently accompany gold. Their luster is 
adamantine, and they are likely to attract the eye 
when found in alluvial deposits, in which they are 
frequently associated with the diamond. 

V. Uranium. Uranium ores are comparatively 
rare. They occur generally associated with other 
minerals, especially silver and tin ores, in veins in 


ZINC, IRON, MOLYBDENUM, TITANIUM. 217 

the older rocks—granite, mica schist, clay slate, 
porphyry. The most important mineral contain¬ 
ing uranium is pitcli-blende or uraninite. It does 
not occur pure but always mixed with other ores— 
silver, tin and zinc ores, galena, pyrites, cobalt, 
nickel and bismuth ores, etc. Color, pitchy black 
to grayish black. Streak, brownish black. Hard¬ 
ness, 5.5. Specific gravity, 9 to 9.7. Luster, pitch¬ 
like to dull. Crystals are rare, generally massive, 
compact, with a conchoidal to uneven fracture. 

Hydrochloric acid does not attack pitch-blende, 
but decomposes carbonates and silicates which may 
be present, as well as metallic sulphides, sulphur¬ 
etted hydrogen being evolved. In a pure state pitch¬ 
blende is soluble in nitric acid, the color of the so¬ 
lution being yellow. It dissolves with difficulty in 
concentrated sulphuric acid, the solution being 
green. The solution in nitric acid gives with am¬ 
monia a sulphur-yellow 7 precipitate. When boiled 
w 7 ith phosphoric acid an emerald-green solution re¬ 
sults. 

The pure ore is next to infusible, colors borax 
yellow in the 0. F., green in the E. F., while micro- 
cosmic salt gives a green color in both flames. 

It may here be noticed that the element radium 
having great radio-activity and closely resembling 
barium in character has been detected in pitch 
blende. 

The chief use of pitch-blende is for the prepara¬ 
tion of an orange color for painting porcelain and 
coloring glass to which it imparts a greenish yellow, 
foggy or opaline appearance. 


218 prospector’s field-book and guide. 

VI. Vanadium is quite widely distributed in 
nature, but is not found anywhere in large masses. 
The principal minerals are 

Vanadinite. In hexagonal prisms, with basal 
pinacoid, also in reniform aggregates of fine col¬ 
umnar to fibrous texture. Color red to brownish 
red. Streak white. Luster, adamantine, on frac¬ 
ture resinous. Hardness, 2.5 to 3. Specific grav¬ 
ity, 6.6 to 7.23. Dissolves readily in nitric acid. 
Decrepitates strongly before the blowpipe, gives in 
the tube a slight white coating, fuses on charcoal to 
a globule which separates lead and give a lead coat¬ 
ing and produces in 0. F. of the borax globule a 
glass, red yellow when warm, yellow green when 
cold, and in the R. F. a beautiful green glass. The 
ore occurs in lustrous red and yellow hexagonal 
crystals in Arizona; in green crystals with calcite 
at Charcas, Mexico, and in Chile. 

Descloizite. Pyramidal, resembling octahedrons, 
drusy. Color, olive green to black. Luster, ada¬ 
mantine to resinous. Hardness, 3.5. Specific 
gravity, 5.839. Gives water in a closed tube. The 
coating on charcoal reacts for zinc with cobalt 
nitrate. It occurs with lead and silver ores. 

Dechenite. Color red, reddish yellow. Streak 
yellowish to orange. Transparent on fracture and 
edges. Occurs in Leadville lead ores. 

Volborthite. Hexagonal. Color, olive green, 
grass green, and yellow. Hardness, 3 to 3.5. 
Specific gravity, 3.45 to 3.55. Streak yellow. 
Gives water in a closed tube and becomes black. 
On charcoal a black slag is formed. 


ZINC, IRON, MOLYBDENUM, TITANIUM. 219 

While vanadium was formerly considered only 
of scientific interest, it has during the past few-years 
sprung into the position of a metal which has prac¬ 
tically marked an epoch in the history of the steel 
trade, its alloys with iron known as vanadium steel 
forming a highly valuable material in the construc¬ 
tion of automobiles, locomotives, etc. 


CHAPTER XI. 


MERCURY, BISMUTH, NICKEL, COBALT, AND CADMIUM. 

I. Mercury or Quicksilver. At ordinary tem¬ 
peratures it is fluid, a character which no other 
metal possesses. The usual properties of a metal 
are, however, highly developed in it, and when 
solid it has much resemblance to silver, especially 
in its high metallic luster, ductility, malleability, 
its capability of being cut with a knife, its granular 
fracture, and its high degree of conductibility of 
heat and electricity. 

Mercury readily combines with most of the other 
metals, and the compounds thus formed are called 
amalgams. The amalgams with the heavy elements 
are generally easy of decomposition, and hence it is 
exceedingly useful for the extraction of gold and 
silver from their ores or matrices. The mercury 
picks up the almost invisible specks of gold, and in 
this way the gold is concentrated into a compara¬ 
tively small space. By heating the amalgam the 
mercury is driven off and the gold is separated in 
nearly pure form. 

Native Mercury. Occurs occasionally as glo¬ 
bules disseminated through the rocks. Color, bright 
white. Specific gravity, 13.6 at 50° F., and about 
( 220 ) 


MERCURY, BISMUTH, NICKEL, COBALT. 221 

15.6 when solid. It contains sometimes a little 
silver, but generally occurs associated with cinnabar, 
the proportion of the latter being, however, very in¬ 
considerable. In more recent formations it occurs 
generally, without cinnabar, in porous rock, some¬ 
times associated with small quantities of chloride 
and iodide of mercury. In California such rock is 
subjected to distillation, if warranted by the price of 
mercury. 

With a higher percentage of silver or gold, mer¬ 
cury is changed to 

Native Amalgams. As in all alloys the propor¬ 
tions of the constituents vary, and the properties of 
a specimen will vary according as the silver, the 
gold, or the mercury predominates. The native 
amalgam most frequently found is a mixture of 
silver and mercury, and when pure contains from 
64 to 72 per cent, mercury. Color, silver-white ; 
hardness, 3 to 3.5; specific gravity, 10.5 to 14. 
Soluble in nitric acid. On charcoal before the 
blow-pipe, the mercury evaporates, and the silver 
remains. 

Amalgams of gold and mercury have been found 
in Utah. 

Selenide of Mercury with 72 per cent, of mer¬ 
cury occurs at Marysvale, Utah, and in Mexico. It 
is of steel or lead-gray color and metallic luster. 

Cinnabar or Sulphide of Mercury. The chief 
supply of commercial mercury is obtained from this 
ore. It is found in granular, fibrous, dense and 
earthy masses, and sometimes also in small rhom- 


222 prospector’s field-book and guide. 

bohedral or prismatic crystals. Specific gravity, 
6.7 to 8.2. Hardness, 2 to 2.5. Streak, scarlet-red. 
Fracture, uneven, splintery. Luster, adamantine. 
Color, generally cochineal-red, also brown, brownish- 
black, etc. Contains, mercury 86.2, sulphur 13.8, 
when pure. Before the blow-pipe in the closed 
tube it yields a black sublimate of the same compo¬ 
sition as the original mineral. In the open tube, if 
carefully heated, it yields sulphurous acid and mer¬ 
cury globules, together with a small quantity of 
black sublimate. On charcoal it volatilizes com¬ 
pletely. Insoluble in sulphuric acid, hydrochloric 
acid and potash lye ; soluble in aqua regia, sulphur 
being separated. 

There is also a black sulphide, called metacinna- 
barite , found in one locality in California ; and, in 
California and Mexico, a sulphoselenide named 
guadalcazarite (81J per cent, mercury, 10 sulphur, 
6J selenium) is sometimes encountered. 

The quicksilver deposits at Almaden, in Spain, 
have a far remote history, for in the time of Pliny 
10,000 lbs. were sent annually to Rome from these 
mines. They occur in upper silurian slates, some¬ 
times interstratified with beds of limestone ; but the 
ordinary slates themselves, which are much con¬ 
torted, rarely contain cinnabar. The enclosing 
rock usually consists of black carbonaceous slates 
and quartzites alternating with schists and fine¬ 
grained sandstones. 

At Idria, Austria, cinnabar is found in impreg¬ 
nated beds and stock works, in bituminous shales, 


MERCURY, BISMUTH, NICKEL, COBALT. 223 

dolomitic sandstones and limestone breccias of tri- 
assic age, dipping 30° to 40°, and covered by car¬ 
boniferous sandstones and shales in a reversed 
position. This deposit has been worked for nearly 
400 years, and is said to become richer as the depth 
increases. 

The quicksilver-bearing belt of California extends 
along the coast range for a distance of about 200 
miles. According to a report by M. G. Rolland, 
these deposits are generally impregnations in the 
cretaceous and tertiary formations. They seem to 
be richer when the beds are more schistose and 
transmuted. They are more or less closely in rela¬ 
tion with serpentines, which are themselves some¬ 
times impregnated with oxide of iron, sometimes in 
quartzose schists, in sandstones, more rarely in 
limestone rocks, limestone breccias, etc. Native 
mercury is found in some magnesian rocks near the 
surface. There are no defined fissures nor veins 
proper. The cinnabar with quartz, pyrites, and 
bituminous substances is sometimes disseminated in 
the rock in fine particles and spots, sometimes forms 
certain kinds of stockworks or reticulated veins and 
nests. The parts thus impregnated congregate and 
form rich zones, the size of which occasionally 
reaches 80 fathoms, and the percentage 35 per cent., 
and flat-like veins or lenticular deposits, the strike 
and dip of which agree with those of the schists of 
the country generally. These rich zones without 
defined limits gradually merge into poor stuff con¬ 
taining half a per cent., or mere traces, and are of 
no value. 


224 prospector’s field-book and guide. 

Sulphur Bank, one of the principal mines, was 
originally worked as a sulphur deposit. Sulphur 
in workable quantities is known to exist in some 
volcanic countries, and volcanic rocks are abundant 
at the California cinnabar mines. 

II. Bismuth. This metal occurs native, of a red¬ 
dish silver-white color. Brittle when cold ; hard¬ 
ness, 2 to 2.5 ; specific gravity, 9.7. Malleable and 
sectile when heated, but breaks under the hammer. 
It carries, sometimes, traces of arsenic, sulphur, tel¬ 
lurium and iron. On charcoal before the blow-pipe, 
it fuses and entirely volatilizes, leaving a coating 
which is orange-yellow while hot and lemon-yellow 
on cooling (this is the trioxide of bismuth). It dis¬ 
solves in nitric acid, but subsequent dilution causes 
a white precipitate. 

Very little bismuth has been found in our coun¬ 
try. The metal occurs on the Continent of Europe, 
associated with silver and cobalt, also with copper 
ores. Although there is but little call for it in the 
arts, a deposit or lode of bismuth w 7 ould be valuable. 

Where it has been found in the United States it 
has been associated with wolfram (tungstate of iron 
and manganese), also with tungstate of lime, with 
galena and zinc blende in quartz. 

Its Geology is the same as that of copper; it 
occurs in veins in gneiss and other crystalline rocks 
and clay slate, accompanying ores of silver, copper, 
lead and zinc. 

III. Nickel. It does not occur native except in 
meteorites. 


MERCURY, BISMUTH, NICKEL, COBALT. 225 

Under the blow-pipe, the test for nickel requires 
care and some pratice. On charcoal, with soda in 
the inner flame, it gives a gray metallic powder, 
attractable by the magnet. In the borax bead in 
the outer flame it gives a hyacinth-red to violet- 
brown while hot, a yellowish or yellow-red when 
cold. In the reducing or inner flame, a gray ap¬ 
pearance is given. These appearances are modified 
by the impurities and the amount of nickel in the 
mineral. The wet process is the only method of 
determining the true value of a nickel-bearing 
mineral. 

Its chief ores are : 

Smaltite, which is a combination of cobalt, iron 
and nickel, and arsenic in varying proportion. It 
will be more fully referred to, later on, under 
Cobalt. 

Nickel arsenide, Copper Nickel or Nicolite. 
Composition : Nickel, 44.1 ; arsenic, 55.9. It looks 
somewhat like pale copper, but contains no copper. 
Hardness, 5 to 5.5 ; specific gravity, 7.2 to 7.8 ; 
streak, pale brownish to black ; luster, metallic ; 
brittle. It frequently contains a little iron, and 
sometimes a trace of antimony, lead and cobalt. 
Dissolves completely in aqua regia; also in nitric 
acid, crystals of arsenious acid being separated by 
cooling. 

If carefully treated under the blow-pipe with 
borax, it will show the iron if present, in the bead, 
and the cobalt and nickel by successive oxidations 
(see under Smaltites later on). But the nickel re- 
15 


226 prospector’s field-book and guide. 

quires special treatment, the detection of which we 
shall speak of in this chapter. 

There is another mineral, not properly an ore, 
called : 

Emerald-nickel, a carbonate of nickel, contain¬ 
ing 28.6 water when pure. It forms incrustations 
on other minerals, like another called 

Millerite, a sulphide of nickel forming tufts of 
very fine acicular, brassy-looking crystals, in cavi¬ 
ties of the red hematite of Sterling Iron Mines in 
Northern New York, and velvety iucrustations on 
ores in the Gap Mine, Lancaster Co., Penna., where 
nickel was found and worked. In the former place 
no nickel abounds, hut in the latter it has in the 
past been found in paying quantities ; the mine is 
now exhausted. But the sulphide forms at the 
latter place vary very much, as examined under 
the microscope, from the acicular crystals found in 
the ores at Sterling, N. Y., and yet they are of the 
same chemical combination. The ore upon which 
the tuffs of velvety covering were found at the Gap 
Mine, is pyrrhotite or sulphide of iron, holding 4 to 
5.9 per cent, nickel in composition ; that of Sterling, 
N. Y., is the red hematite. 

The sources of nickel discovered in Sudbury, 
Canada, north of Georgian Bay, yield nickel in 
'pyrrhotite (sulphide of iron), and apparently also in 
chalcopyrite, whose typical composition is copper 
34.6, iron 30.5, sulphur 34.9. It is a mineral of 
brass-yellow appearance, and one which furnishes 
the copper of commerce at the Cornwall Mines 


MERCURY, BISMUTH, NICKEL, COBALT. 227 

(Eng.) and at the copper beds in Fahlun, Sweden. 
In the latter place it is imbedded, as it appears to 
be in the region of the Sudbury Mines, only that 
the Sudbury ore is imbedded in pyrrhotite and the 
Swedish in gneiss. 

The chalcopyrite does not mix intimately with 
the nickel ore so as to form a homogeneous mass: 
it occurs by itself in pockets or threads, etc., but in¬ 
closed with massive pyrrhotite, which, while it may 
have more than 30 per cent, of nickel present, does 
not show any sign of the changed composition.* 

This per cent, is far above the average of nickel 
in the pyrrhotite, which seldom carries less than 2J 
per cent, or more than 9 per cent, of nickel. 

The following new ores of nickel are reported by 
Dr. Emmons from Sudbury, Canada: 

Foleyrite, of a bronze-yellow color, grayish-black 
streak, and metallic luster. It occurs massive and 
contains 32.87 per cent, of nickel. Its specific 
gravity is 4.73, hardness 3.5. 

Whartonite contains 6.10 per cent, of nickel. It 
has a pale bronze-yellow color, black streak and 
metallic luster. Specific gravity about 3.73 ; hard¬ 
ness about 4. 

Jack’s Tin or Blueite contains 3.5 per cent, of 
nickel. It is of an olive-gray to bronze color, me¬ 
tallic luster and black streak. Specific gravity, 4.2; 
hardness, 3 to 3.5. 


Dr. E. B. Peters, Manager of the Canada Copper Company. 


228 prospector’s field-book and guide. 

ANALYSIS OF ORES FOR NICKEL AND COBALT. 

As this analysis requires care, we give the follow¬ 
ing method in full : 

1. Reduce finely 50 grains of the ore. Put it in 
a dry beaker-glass and pour over it a mixture of one 
part sulphuric acid with three parts nitric acid, 
both pure and concentrated, or 40 to 50 c. c. to 2 
grams of ore. 

2. Heat the covered beaker on a sand-bath to 
near 212° Fahr. for two hours. Then partly un¬ 
cover, and evaporate the nitric acid entirely. 

3. Cool and add 100 or more c.c. of water and 
let it stand for four hours; the insoluble residue is 
lead sulphate, silex, etc. 

4. Filter off the soluble part and place the moist 
lead sulphate in a beaker and dissolve it by first 
pouring in ammonia (20 to 25 c.c.), and next acetic 
acid till it is decidedly acid. The sulphate now 
dissolves if kept warm for some twenty minutes. 
Filter and wash, and if any residue remains (silex, 
etc.), reserve for future examination. 

5. The lead is now separate, but if the amount 
is sought, pass a current of hydrogen sulphide 
through the solution till the lead is entirely pre¬ 
cipitated. Filter, dry, place the residue in a porce¬ 
lain crucible and heat to a low red heat, passing a 
current of dry hydrogen into the crucible while 
heating, to prevent any oxidizing of the sulphide. 
When the crucible and contents remain the same 
in weight, the last weight of the lead sulphide is the 
correct amount. Of this weight, 86.61 parts in 100 
are lead, 13.39 are sulphur. 


MERCURY, BISMUTH, NICKEL, COBALT. 229 

If the ore has no lead in it, the above work is 
omitted entirely. The likelihood of lead may be 
tested qualitatively from a small quantity dissolved, 
precipitated by hydrogen sulphide, and the precipi¬ 
tate determined by the blow-pipe on charcoal giving 
the lead coating, and with soda, the metallic globule. 

6. To separate the copper. The filtrate re¬ 
maining after the insoluble lead sulphate was fil¬ 
tered off, as in No. 4, now contains whatever the 
mineral is composed of, copper, iron, nickel, cobalt, 
etc. Dilute the filtrate to about 500 c.c., heat to 
nearly boiling, and pass hydrogen sulphide through 
it, and thus precipitate all the copper after adding 
1 or 2 c.c. of hydrochoric acid. Filter, wash, dry, 
and ignite the precipitate in an atmosphere of 
hydrogen. The result will be pure Cu 2 S, from 
which the copper may be ascertained as 79.85 parts 
of the w T hole weight of Cu 2 S. 

7. Concentrate by evaporation the filtrate of No. 
6 remaining after the copper was separated, add 
1 or 2 c.c. of nitric acid, and boil the filtrate two 
or three minutes, let it become nearly cold, add an 
excess of ammonia, and let it stand in a warm place 
half an hour. 

8. Filter the precipitate into a porcelain dish and 
redissolve the iron oxide (hydroxide) with hydro¬ 
chloric acid poured slowly into the filter, complete 
washing of the filter with hot water, reduce the free 
acid in the filtrate with ammonia, then very nearly 
neutralize it carefully with sodium (metallic) or 
ammonium carbonate; the solution must remain 


230 prospector’s field-book and guide. 

clear, though dark red, if much iron is present. 
Now add a strong neutral solution of ammonium or 
sodium acetate (not in large excess), and then boil 
a short time. When rightly performed the iron 
oxide precipitate will settle rapidly, and the super¬ 
natant liquor will be clear. Wash rapidly with 
boiling water, and, at first, separate the clear part 
by decantation, and then filter. If great exactitude 
is required, redissolve in hydrochloric acid, and 
once more precipitate with the acetate just as before. 
Add this filtrate to the ammoniacal filtrate men¬ 
tioned at the beginning of No. 7 paragraph. 

The iron is now separated as basic ferric acetate, 
and it is almost, if not entirely, separated from all 
nickel and cobalt which are yet in solution. 

9. The first filtrate, No. 7, contains all the nickel 
and cobalt. It must now be concentrated to about 
250 c.c. If it is slightly acid, proceed ; if not, then 
add muriatic acid until it is very slightly acid. 
Now heat the filtrate in a beaker to gentle boiling, 
and pass hydrogen sulphide through the liquid. A 
black precipitate follows; if nickel sulphide with 
cobalt sulphide, they are together. 

10. Filter, wash, and dry; incinerate the filter- 
paper with the precipitate if very small in quantity, 
otherwise separately; heat in porcelain crucible. 
Dissolve in aqua regia (nitro-muriatic acid), and 
treat it till only yellow sulphur remains, evaporate 
and expose the residue to a heat of 180° Fah. to 
make any silica insoluble. Moisten with a few 
drops of muriatic acid, add 20 c.c. of water to dis- 


MERCURY, BISMUTH, NICKEL, COBALT. 231 

solve the salts, add some solution of hydrogen sul¬ 
phide to separate any copper or lead which may 
have escaped separation, filter into a porcelain dish 
and concentrate all to about 100 c.c. 

11. Boil gently, and while boiling add pure so¬ 
dium carbonate solution until the liquid is slightly 
alkaline. Continue boiling a few minutes, add a 
few grains of pure soda solution (sodium hydroxide). 
This is best prepared freshly by dropping a small 
ball of metallic sodium into a half ounce of water 
in a platinum dish or crucible, or not so well, in a 
porcelain dish. Heat to boiling again a few min¬ 
utes till all the nickel and cobalt are precipitated, 
wash the precipitate with boiling hot water by de¬ 
cantation, and finally on the filter, until a drop on 
polished platinum shows no residue. After drying 
the precipitate remove it to a piece of glazed paper; 
cover with a bell-glass. Then incinerate the filter 
till the carbon has entirely disappeared, add it to 
the precipitate already obtained, place all in a cru¬ 
cible, cover it and expose to heat to redness, and, 
finally, if desired, reduce the oxides to the metallic 
condition by ignition under a stream of hydrogen. 

12. As this process of reduction to metal is some¬ 
times very useful, we give a simple plan of appa¬ 
ratus for this purpose. Get a half-pint wide¬ 
mouthed pickle bottle and introduce two glass tubes 
of a quarter-inch diameter into a cork fitting the 
mouth, after having nicely adjusted the cork to the 
mouth of the bottle. The tubes may be easily bent 
and blown as in A B, Fig. 60, over the flame of an 


232 prospector’s field-book and guide. 

alcohol lamp, before permanently fastening them in 
place. To blow a funnel end, heat the end of the 
tube to softness and mash it together, hermetically 
seal, then reheat rapidly, roll it between finger and 
thumb while gently blowing at the other end until 
swollen large enough, then with pincers, break it 
or chip it off ; if enlarged twice or three times the 


Fig. 60. 



diameter, it is large enough for the purpose. The 
tubes intended to be bent should be rapidly rotated 
in the enlarged flame until red-hot, and then bent 
to the right angle and gradually cooled. 

It is well to make another of these bottles for dry¬ 
ing the hydrogen, as in B. Introduce the tube as 
shown in the figure, wherein B represents the dry¬ 
ing bottle in which is placed a quantity of fragments 
of chloride of calcium of the size of peas or even 
smaller. In putting the cork with tubes into this 
bottle, the bottle should be on its side and rolled 
while introducing the longer tube into the calcium 


























MERCURY, BISMUTH, NICKEL, COBALT. 233 

chloride, so that the fragments may not obstruct 
the tube as it is pushed down. The exit-tube may 
be bent or straight, and properly-sized india-rubber 
tubing may be fitted over the ends so as to make 
connections. A common clay-stem smoking pipe 
arranged as in the figure, with the bowl inverted 
into the crucible which is placed on a wire support 
on a retort stand, c, is quite sufficient. The usual 
alcohol blast-lamp, d, is required for this operation. 
To put the apparatus to work it is only necessary to 
introduce some three or four ounces of broken-up 
pieces of zinc into A, together with water sufficient 
to half fill the bottle, cork up with the tubes ar¬ 
ranged as above, and pour into the funnel-shaped 
tube common oil of vitriol gradually, until the gas 
begins to come over, then stop as the water becomes 
heated, and the gas will increase without further 
addition. You may now prepare your crucible, 
and, when in place, and the tubes all arranged, the 
gas may be made to come over more rapidly by 
adding a little more oil of vitriol, drop by drop. 

13. The crucible should be weighed after cooling 
and replaced, the flame of the blast-lamp relighted, 
and red heat renewed under the hydrogen apparatus 
until the crucible, when again weighed, shows no 
alteration in weight. The oxide has now been re¬ 
duced to the pure metal form, and it may then be 
cooled. 

In the case of the analysis we are now upon, the 
metallic reduction will be that of both nickel and 
cobalt, and they will appear as a dark powder in 
the bottom of the crucible. 


234 prospector’s field-book and guide. 

When the hydrogen apparatus is no longer to be 
used, the generator bottle A should be washed thor¬ 
oughly and the zinc also; the latter may be left in 
the bottle and the cork replaced loosely, but the 
cork must be removed from bottle B, and a tight- 
fitting cork be used in its place,, as the chloride may 
be used again. All is ready for another operation 
by simply replacing and adding water and acid as 
before. 

4. Separation of Nickel and Cobalt. The 
two metals should be weighed in order that, if the 
cobalt be found, the nickel may be known by the 
difference. Dissolve the two metals in nitric acid 
and evaporate them till there is no free nitric acid. 
Next add about 6 to 8 grams (100 grains) potas¬ 
sium nitrate dissolved in 10 to 15 c. c. of hot water. 
If any flocculent particles appear, add a little 
acetic acid, just sufficient to dissolve them, and 
now a precipitate of cobalt (as tripotassium cobaltic 
nitrate), takes place slowly. The whole volume 
should now be 15 to 20 c.c. Cover the beaker con¬ 
taining it with glass, and set it aside in a warm 
place for twenty-four hours. Filter, wash with a 
solution of potassium acetate (which may be made 
by neutralizing acetic acid with crystallized potas¬ 
sium bicarbonate, leaving the solution slightly 
acid), and proceed to more efficiently separate the 
cobalt as a metal, as follows: 

Dilute the filtrate, heat, and precipitate with 
caustic soda (sodium hydroxide), wash the greater 
part of the saline matter out, and then dissolve the 


MERCURY, BISMUTH, NICKEL, COBALT. 235 

precipitate in nitric acid, evaporate to dryness, add 
two or three drops of nitric acid and dissolve in a 
small volume of water, filter, concentrate the fil¬ 
trate, and repeat the process of separation of potas¬ 
sium nitrate as before. Put this precipitate, with 
the filter-paper, into a beaker, add about 100 c.c. of 
water, heat, add muriatic acid to dissolve it, separate 
the filter-paper, wash it in a funnel, evaporate 
the solution on a water-bath, and let it remain on 
the water-bath two or three hours to render the 
silica insoluble, then moisten with muriatic acid, 
add water, filter, and convert the cobalt to metallic 
form, as was done before for both nickel and cobalt, 
namely, as in paragraph No. 11. The cobalt is 
now entirely separate from the nickel. Weigh it, 
and by difference from the weight of the two deter¬ 
mine the weight of nickel as suggested in No. 14. 
The amount of nickel is now known by weight, 
and readily compared with the whole amount 
of the original weight of ore employed at the 
beginning. 

If the above process is carefully followed out, in a 
mineral containing lead, copper, iron, cobalt, and 
nickel, the cobalt and nickel are separated with 
great exactness. 

However, the main ore of nickel is pyrrhotite, 
and as found in the Sudbury Mines, Canada, it 
contains only iron and nickel, seldom cobalt enough 
to notice. So that much less work is required, as 
follows: Pulverize, dissolve in muriatic acid in a 
flask. If very much free acid is present, nearly 


236 prospector's field-book and guide. 

neutralize with sodium or ammonium carbonate; 
the solution should be clear, but, if there is much 
ferric chloride, it should be of a deep-red color; 
now do as directed in No. 8, to add the ammonium 
acetate, and proceed as before. 

In addition to the nickel ores already given may 
be mentioned a hydrated silicate of nickel found in 
New Caledonia and named after its discoverer. 

Garnierite. It contains from 8 to 10 per cent, 
of nickel. Color, light or dark green. Streak, 
light green. Specific gravity, 2.2 to 2.86. Hard¬ 
ness, 2.5. Fuses in borax before R. F. and gives 
the ordinary nickel bead. It is found in lodes and 
pockets in serpentine rock. It has also been found 
in Oregon. 

IV. Cobalt. Cobalt does not occur in native 
form. The following are the minerals of import¬ 
ance : 

Smaltite seems to be composed of cobalt, nickel, 
iron and arsenic ; the typical form is arsenic 72.1, 
cobalt 9.4, nickel 9.5, iron 9 = 100. Hardness, 
5.5 to 6 ; specific gravity, 6.4 to 7.2. Color, tin- 
white, sometimes iridescent. Streak, grayish-white. 
Brittle. Before the blow-pipe, on charcoal with 
soda, the arsenious acid fumes are given off, and 
the garlic smell is plainly observed. With borax 
for the bead the assay may be made to show (with 
successive heatings) the reactions, first of iron, then 
cobalt, and nickel, provided the operator is skilful 
in oxidizing the powdered ore by cautious degrees; 
when one borax bead shows iron reaction by a cer- 


MERCURY, BISMUTH, NICKEL, COBALT. 237 

tain amount of carefully applied OF to the bead, 
try another with increased degree of oxidation until 
you perceive the cobalt blue and nickel brown, 
if both are present. 

Cobaltite is composed of sulphur, arsenic and 
cobalt in the typical proportions of 19.3, 45.2, 35.5 
= 100, but it frequently, as a mineral, contains iron. 
Hardness, 5.5; specific gravity, 6 to 6.3. Under the 
blow-pipe, in an open tube, it sends off sulphurous 
fumes and a sublimate of arsenious acid. With borax 
bead gives the blue of cobalt. Dissolves in warm 
nitric acid, separating the sulphur and arsenic. 

Cobaltite and smaltite are valuable as affording 
the greater part of the smalt of commerce, and the 
former is used in porcelain painting. 

Erythrite is a soft (1.5 to 2.5) peach-red mineral 
of specific gravity 2.9, transparent or translucent, 
sometimes pearl- or greenish gray. 

Composition, typical, arsenic, 38.43, cobalt oxide, 
37.55, water, 24.02 — 100. 

In a closed tube, under blow-pipe, it yields water 
and turns bluish. Gives the usual blue for cobalt 
in the borax bead. 

Valuable for the manufacture of smalt. It is 
sometimes known as “ cobalt bloom.” 

Linn^ite. This is valuable for the large amount 
of both cobalt and nickel it sometimes contains. 
Hardness, 5.5; specific gravity, 4.8 to 5; metallic lus¬ 
ter ; color, pale steel-gray, tarnishing to red. Com¬ 
position, sulphur, 42, cobalt 58 = 100, but cobalt is 
replaced by large amounts of nickel, and sometimes 
copper. Some specimens from Mineral Hill, Mary- 


238 prospector’s field-book and guide. 

land, and from Missouri, have yielded as high as 
29.56 and 30 per cent, of nickel, with 21 to 25 per 
cent, cobalt in the same specimen, but with a small 
amount of iron (3 per cent.). 

Earthy Cobalt or Cobalt Wad (Asbolite is the 
mineralogical name), occurs as a bog ore, with man¬ 
ganese, iron and copper, and nickel. It is blue, 
black at times, has a hardness of 1 to 1.5, and 
specific gravity of 2.2 to 2.6. It sometimes contains 
up to 35 per cent, of cobalt oxide. 

The geological position of cobalt is in the earlier 
rocks, as the chlorite slates with chalcopyrite, 
blende, and pyrite, as in Maryland. Sometimes 
the ore is found in cavities in the limestone of 
the carboniferous age, as in Great Britain. The 
tin-white cobalt is found in the gneissic and prim¬ 
itive rocks as in Norway. Linnseite is found at 
Mine la Motte, Mo., in masses, sometimes in octa¬ 
hedral crystals among its rich ores of lead and nickel. 

IV. Cadmium. Of this mineral but one ore is 
known, namely, the sulphide, or Greenockite, with 
77.7 per cent, cadmium. Color, honey- to orange- 
yellow and brick-red ; in hexagonal prisms ; hard¬ 
ness 3 to 3.5 ; specific gravity 4.5 to 4.908. Before 
the blow-pipe, on charcoal with soda, it yields a red- 
brown deposit. Cadmium is frequently associated 
with zinc ores, some varieties of sphalerite or blende 
containing 3.4 per cent. 

Metallic cadmium is white like tin, and shares 
with it the property of emitting a crackling sound 
when bent. It is so soft that it leaves a mark upon 
paper. 


CHAPTER XII. 


ALUMINIUM, ANTIMONY, MANGANESE. 

1. Aluminium. The distribution of aluminium 
in nature is very wide, rivaling that of iron, yet three 
are but few minerals which serve as sources of the 
metal. These are : Bauxite, a limonite in which most 
of the iron is replaced by aluminium. It occurs 
in earthy masses resembling clay ; also in compact 
form. The color varies from white to gray, yellow 
also to brown or red, especially in the impurer kinds. 
It contains 50 to 75 per cent, alumina. Corundum, 
generally quite pure but too valuable for abrasive 
purposes to be used as an ore. It will be more fully 
described in Chapter XV, Gems and Precious 
Stones, this mineral species including some of the 
most important precious stones. Diaspore hard and 
crystalline, specific gravity 3.4, with 64 to 85 per 
cent, alumina, and ordinarily quite pure. Gibbsite , 
stalactitic, specific gravity 2.4, containing, when 
pure, 65 per cent, alumina. Aluminite, specific grav¬ 
ity 1.66, a sulphate of aluminium found in large 
beds, chiefly along the Gila River, in New Mexico, 
containing about 30 per cent, alumina, and easily 
soluble in water. Cryolite , specific gravity 2.9, easily 
fusible, and when fused its specific,gravity is about 
2. It contains 40 per cent, aluminium fluoride 
(239) 


240 prospector’s field-book and guide. 

and 60 per cent, sodium fluoride. All clays con¬ 
tain a large percentage of aluminium, but always 
in the state of silicate, and the difficulty of remov¬ 
ing this silica has so far prevented the employment 
of clay as an ore of aluminium. 

Of the ores above named the most important is 

Bauxite, of which there are vast deposits at 
Baux, near Arles, in France, in Ireland, and in 
Alabama, Arkansas, the Carolinas, Georgia, Ten¬ 
nessee and Virginia. 

The Arkansas deposits are said to cover a large 
area, and to reach a thickness of 40 feet, forming 
an interbedded mass in ferruginous Tertiary sand¬ 
stone. 

The Alabama deposits are better known, and all 
occur in the lower Silurian formation. The dis¬ 
trict has been badly broken up by sharp folds and 
great thrust faults, and the mineral occurs as 
pockets in close association with brown iron ore 
(limonite) and clay. 

Bauxite has to undergo purification for the pur¬ 
pose of the aluminium manufacturer. Several 
methods are used: 

1. It is chosen as free from iron as possible, and 
is roasted at a low red heat, and afterwards treated 
with sulphuric acid, which combines with the alu¬ 
mina present, forming sulphate of alumina. This 
is readily dissolved by water, leaving the great bulk 
of silica and iron behind. The solution of sulphate 
of alumina is allowed to settle, the supernatant 
liquid is siphoned off into an evaporating tank and 


ALUMINIUM, ANTIMONY, MANGANESE. 241 

evaporated to dryness. The dry sulphate of alu¬ 
mina is calcined at a red heat, driving off the sul¬ 
phuric acid, leaving as a residue anhydrous alumina. 

2. The bauxite is treated either by fusing with 
carbonate of soda and dissolving in water, or by 
boiling it with a strong solution of caustic soda. 
In either case a solution of sodium aluminate is ob¬ 
tained, which is filtered from the residue of silica 
and ferric oxide, and decomposed into aluminium 
hydrate and carbonate of soda by pumping carbonic 
acid gas through it. After a thorough washing, 
the hydrate is calcined at a high heat, and the re¬ 
sulting alumina is finely ground. 

If not too darkly colored, due to iron, bauxite 
gives the blue-colored mass characteristic of alu¬ 
minium when ignited after moistening with cobalt 
nitrate. 

The ore next in importance is 

Cryolite, of which there is practically only one 
productive mine, that at Ivigtut, South Greenland. 
The mine is worked as a quarry, and has been 
opened 450 feet long, 150 feet wide and 100 feet 
deep, while diamond drills have proved the perma¬ 
nence of the ore for a further depth of 150 feet. 
The vein appears to widen with depth, hut the 
quality of the mineral becomes inferior. About 
10,000 tons of cryolite annually are shipped to the 
United States. 

With the blowpipe, on charcoal, cryolite fuses to a 
clear bead, becoming opaque on cooling. After long 
blowing with O F the assay spreads out, the fluoride 
16 


242 prospector’s field-book and guide. 

of sodium sinks into the charcoal, and the suffo¬ 
cating odor of fluorine is given off and the alumin¬ 
ium remains as a crust which, if touched with a 
little cobalt solution and gently heated, gives a blue 
color of alumina. If some of the cryolite is pow¬ 
dered and placed near the open end of a glass tube 
and the flame from the blowpipe turned carefully 
on it, the fluorine will be freed and will etch the 
glass, showing corrosion and proving the presence 
of fluorine. Besides, as a source of the metal alu¬ 
minium, cryolite is used as a flux, and largely for 
the manufacture of alumina of soda. 

While the older processes of aluminium manu¬ 
facture, dependent on the reduction of the double 
chloride of aluminium and sodium, must always 
have a scientific interest, they have been beaten out 
of the field of commercial industry by the new r er 
electrolytic methods, of which there are four vari¬ 
eties. In England and America Cowles’ and Hall’s 
patents are followed ; on the Continent, Heroult’s 
and Minet’s. They are all virtually modifications 
of the original Deville-Bunsen process, maintaining 
fusion by the heat of the electric current. 

II. ANTIMONY. This metal occurs in three 
forms, namely, the oxide, senarmontite , containing 
83.56 per cent, antimony ; the sulphide, stibnite, 
antimonite or antimony glance , affording 71.8 per 
cent.; a sulphoxide, kermesite , giving 75.72 per 
cent., in addition to some unimportant combina¬ 
tions with silver, etc. While it may be said that 
antimony is somewhat widely distributed in nature, 


ALUMINIUM, ANTIMONY, MANGANESE. 243 

yet, owing to cost and difficulties in extraction, only 
comparatively few mines affording a rich ore can 
be profitably worked. Beyond the considerable 
quantities of oxide coming from Algiers and of ker- 
mesite from Tuscany, almost the entire output is in 
the form of 

Stibnite, which contains 78.8 per cent, antimony 
and 28.2 sulphur. Hardness, 2 ; specific gravit}^ 
4.5. Color, lead-gray; streak blackish lead-gray, 
rubbed streak is pale yellowish-brown. Luster, 
metallic ; sectile. Occurs in rhombic, generally in 
radiated or divergent bunches ; massive with col¬ 
umnar or fibrous structure. Soluble in hydro¬ 
chloric acid giving a slight crystalline precipitate 
of lead chloride if lead be present. 

Before the blowpipe, on charcoal, it fuses, spreads 
out, gives sulphurous and antimonious fumes, coats 
the charcoal with white oxide of antimony ; this 
coat, treated in R F, tinges the flame greenish-blue. 

Foremost in antimony production stands Por¬ 
tugal, due principally to the mining district of 
Oporto. The geological formations of Portugal are 
chiefly igneous and old sedimentary. The most 
favorable rocks for good antimony ore are bluish 
gray argillaceous Silurian shales. 

Among the other European centers of production, 
the Bohemian mines are in granite and mica schist; 
the Hungarian in granite—sometimes auriferous; 
the Styrian in dolomite, and the Turkish also in 
granite. Victoria, New South Wales, and Western 
Australia are large producers of auriferous stibnite. 


244 prospector’s field-book and guide. 

In New Brunswick, antimony is mined in a quartz 
and calcite gangue in clay-slates and sandstones of 
Cambro-Silurian age. 

Within the United States stibnite has been found 
in a number of places, all in the West. At San 
Emigdio, Kern Co., California, it is contained, with 
quartz gangue, in a vein in granite. The vein 
varies in thickness from a few T inches to several feet. 
Several other small deposits occur in San Benito 
Co. and elsewhere in California. Stibnite has also 
been discovered in Humboldt Co., Nevada, and in 
Louder Co., not far from Austin, in a quartz gangue. 
Some remarkable deposits occur in Iron County, 
Utah, as masses of radiating needles, which follow 
the stratitication planes of sandstone and fill the 
interstices of a conglomerate. Stibnite is found in 
Sevier Co., Arkansas, filling veins, with a quartz 
gangue, in sandstone. 

III. MANGANESE, The ores of manganese are 
divided into three general classes : 

1. Manganese ores. 

2. Manganiferous iron ores. 

3. Argentiferous manganese ores. 

Wad is the name given to manganese oxide. It 
is found in earthy, compact masses of a dark brown 
color, chiefly oxide of manganese and water. 

Easily recognized under the blow-pipe, as it gives 
(in minute quantities) in the borax bead, a violet 
color in the 0 F, but disappears when the R F is 
turned upon it, and reappears when the 0 F is 
repeated. 


ALUMINIUM, ANTIMONY, MANGANESE. 245 

It is found in beds varying from several inches to 
a foot or more in thickness. Hardness, 0.5 to 2.5 ; 
specific gravity, 3 to 4. Color, generally some. 
shades of dark-brown ; streak umber-brown. Gen¬ 
erally soft and earthy, compact. Fracture smooth, 
sometimes sub-conchoidal. Wad is used as a flux in 
iron smelting, and in a lixiviated state as a paint. 

Pyrolusite. This is the peroxide or dioxide, 
with 63.2 per cent, of manganese and 36.8 per cent, 
oxygen. Its crystalline form is the rhombic prism 
and it generally occurs in the form of minute crys¬ 
tals grouped together and radiating from a common 
center. It has an iron-black or steel-gray color, a 
semi-metallic luster, and yields a black streak. 
Specific gravity, 4.7 to 4.86; hardness, 2 to 2.5; 
infusible before the blow-pipe, and acquires a red- 
brown color. On heating it generally yields some 
water and loses 12 per cent, of oxygen. With 
borax, sgda and microcosmic salt it shows man¬ 
ganese reaction. It dissolves in hydrochloric acid, 
when heated, with vigorous evolution of hydrogen. 

Psilomelane occurs massive, occasionally shelly, 
seldom fibrous ; color, iron-black to bluish-black 
streak bluish-black and shining; fracture, con- 
cnoidal to smooth. Specific gravity, 3.7 to 4.7 ; 
hardness, 5.5 to 6. Before the blow-pipe it yields 
manganic oxide, giving off oxygen. It is soluble 
in hydrochloric acid, chlorine being evolved. The 
powdered ore colors sulphuric acid red. Psilome¬ 
lane contains from 40 to 50 per cent, of manganese, 
and some baryta and potassa. A solution in hydro- 


246 prospector’s field-book and guide. 

chloric acid of the variety containing baryta gives 
a heavy white precipitate with sulphuric acid. 

Rhodocrosite or Manganese Carbonate occurs 
in spherical and nodular aggregations of cauliform 
texture or in compact masses of granular texture. 
It is rose-red to raspberry-red in color, by weather¬ 
ing frequently brownish, with a glassy or mother- 
of-pearl luster. It cleaves like calcite. It contains 
61.4 per cent, of manganese protoxide and 38.6 per 
cent, of carbonic acid, with part of manganese fre¬ 
quently replaced by calcium, magnesium, or iron. 
Specific gravity, 3.3 to 3.6; hardness, 3.5 to 4.5. 
Before the blow-pipe it is infusible and becomes 
black. From similar minerals it is distinguished 
by its rose-color and the manganese reaction with 
soda and borax ; and from silicate of manganese by 
its inferior hardness, its effervescence with acids and 
its non-fusibility. 

The manganese in ores of the third class is valu¬ 
able, even when the silver alone is sought, as it 
facilitates the work whereby the silver is extracted ; 
this it does because of its fluxing quality. 

In the United States the most important mines of 
manganese are located in Virginia, Arkansas and 
Georgia. The chief production in Virginia is at 
the Crimona mines, in Arkansas in the Batesville 
district, and in Georgia in the Cartersville district. 
In the latter district extensive deposits of man¬ 
ganese are closely associated with deposits of iron 
ore. All the iron ore contains traces of manganese, 
but the main deposits of the latter are quite distinct 


ALUMINIUM, ANTIMONY, MANGANESE. 247 

from the iron. The ore occurs like the brown 
hematite, embedded in a heavy mantle of residual 
clay, associated with chert and angular fragments 
of quartzite. The proportion of clay to ore is gen¬ 
erally larger than in deposits of brown hematite. 
The ore occurs as small concretions scattered 
through the clay, and also in the form of veins, 
penetrating the clay in an irregular manner. It 
has the appearance of having been deposited by 
solutions percolating through the residual mantle. 
The original source of the manganese was probably 
the Beaver limestone, although some of it may have 
come from the Weisner quartzite. The deposits 
occur with about equal frequency in the residual 
material derived from the two formations. 

In California manganese is produced in a small 
way for use in the manufacture of chlorine for gold¬ 
smelting purposes. 

Colorado produces two classes of manganese-bear¬ 
ing ores, a manganiferous iron ore used to some 
extent in the production of spiegeleisen, and a man¬ 
ganiferous silver ore used as a flux in the smelting 
of silver-lead ores. 

A deposit of manganese has also been opened in 
the Chickasaw Nation, Indian Territory. 

The greater portion of manganese and mangan¬ 
iferous ores serves for the preparation of iron man¬ 
ganese alloys—spiegeleisen and ferro-manganese, as 
well as other manganese alloys. Considerable 
quantities are used as coloring matter in the manu¬ 
facture of pottery and glass. 


248 prospector’s field-book and guide. 

Manganese, when heated in the air, gives a good 
brown paint, and when moderately heated a black 
paint. Both paints may be directly produced from 
the residues resulting in the manufacture of chlorine. 

Manganese is also used as a coloring matter and 
mordant in dyeing and calico printing, in the 
manufacture of oxygen, as a material in the manu¬ 
facture of disinfectants, and in electrical batteries. 


CHAPTER XIII. 


VARIOUS USEFUL MINERALS. 

Alum. This name is applied to a group of min¬ 
erals which are hydrous sulphates of aluminium 
with potash, soda, ammonia, magnesia, etc. They 
all crystallize in the regular system, are soluble in 
water and have an astringent sweetish taste. Hard¬ 
ness, 2 to 2.5 ; specific gravity, 1.8. Potash alum 
is the most common, and is usually found in the 
form of an efflorescence or an incrustation, with a 
mealy and sometimes a fibrous structure. It is 
abundant in clays, argillaceous schists, which, when 
largely impregnated with alum, are called aluminous 
schists or shales. 

Soda alum has a general resemblance to potash 
alum but is rather more soluble in water. Magnesia 
alum occurs in silky-lustered fibrous masses. Iron 
alum forms yellowish-white silky masses. It differs 
somewhat from the other alums in turning red 
when heated. 

Alum is used in dyeing and calico-printing, can¬ 
dle-making, dressing skins, clarifying liquids, and 
in pharmacy. 

Apatite, Phosphate of Lime, occurs in six- 
sided prisms, also in masses. It is transparent or 
opaque; colorless, white, yellowish, green, violet, 
(249) 


250 prospector’s field-book and guide. 

with a glassy luster, and yields a white streak. 
Fracture, conchoidal or uneven. Specific gravity, 
3.16 to 3.22. Hardness, 5. In thin laminae it is 
fusible with difficulty before the blowpipe; when 
moistened with sulphuric acid, it tinges the flame 
greenish. It is soluble in hydrochloric and nitric 
acids without effervescence. From beryl it is dis¬ 
tinguished by its inferior hardness and its solubility 
in acids. It occurs in rocks of various kinds, but 
more frequently in those of a metamorphic crystal¬ 
line character, as in Laurentian gneiss, which is 
usually hornblendic, granitic or quartzose in char¬ 
acter, in Canada, and in association with granular 
limestone. It is also found as an accessory mineral 
in metalliferous veins, especially those of tin, and 
beautifully crystallized and of various colors in 
many eruptive rocks. It also occurs in veins by 
itself, mostty in limestone, but sometimes in gran¬ 
ites and schists. In these deposits apatite is also 
found as concretions, sometimes showing a radiated 
structure, but of an earthy appearance externally. 

In sedimentary formations where a considerable 
accumulation of fossils has provided the phosphate 
of lime it occurs in two principal forms, namely, 
coprolites, which are excreta of large animals, 
especially saurians, and concretions formed at the 
expense of the same coprolites, together with shells, 
bones, etc. The richest of these deposits are from 
Lower Cretaceous to Lower Jurassic in age, but 
phosphatic deposits are found and worked in sedi¬ 
mentary deposits of all ages. 


VARIOUS USEFUL MINERALS. 251 

The principal use of apatite is as a source of phos¬ 
phoric acid and phosphorus, and before the dis¬ 
covery of the phosphate-rock deposits in Florida 
was largely sold to the manufacturers of fertilizers. 

The Tennessee white phosphates occurs in Perry 
and Decatur counties. The lamellar variety is the 
highest grade and the most easily prepared for 
market. It also appears to be most abundant. 
Selected specimens of the thin plates contain 85 to 
90 per cent, of lime phosphate. The less dense 
greenish material, which is associated with the 
white and pink plates, contains some ferrous iron 
and runs slightly under 80 per cent, of lime 
phosphate. 

Arsenic is found in the mineral kingdom partly 
in a metallic state, partly in combination with 
oxygen, sulphur and other bodies. 

1. Native Arsenic occurs seldom distinctly crystal¬ 
lized, but usually in fine granular, spherical or 
nodular masses. Specific gravity, 5.7 to 5.8 ; hard¬ 
ness, 3.5 ; brittle ; uneven and fine-grained fracture ; 
metallic luster ; color, whitish lead-gray, usually 
with a grayish-black tarnish ; evolves an odor of 
garlic on breaking ; contains occasionally more or 
less iron, cobalt, nickel, antimony and silver. 

Before the blow-pipe it quickly volatilizes before 
fusing, giving off white fumes having an odor of 
garlic. Native arsenic occurs especially in veins in 
crystalline slates and transition rocks in subordinate 
quantities associated with ores of silver, lead, cobalt 
and nickel. 


252 prosBector’s field-book and guide. 

2. Realgar , with 70.029 per cent, of arsenic and 
39.971 per cent, sulphur. Color, red ; crystallizes 
clinorhombic; fracture, conchoidal to splintery; 
hardness, 1.5 to 2.0 ; specific gravity, 3.4 to 3.6. It 
is but slightly affected by acids ; soluble with a de¬ 
posit of sulphur in aqua regia, and in concentrated 
potash lye with separation of dark brown sulphuret 
of arsenic. From ruby silver and cinnabar, it is 
readily distinguished by its inferior hardness, 
slighter specific gravity and orange-yellow streak, 
the streak of the two above-mentioned minerals 
being cochineal-red. 

3. Orpiment , with 69.9 per cent, of arsenic and 
39.1 per cent, of sulphur; occurs in nature, but for 
industrial purposes is mostly artificially prepared. 
The mineral has a lustrous lemon-yellow or orange- 
yellow color, is cleavable into thin, flexible, trans¬ 
parent laminae ; hardness, 1.5 to 2 ; specific gravity, 
3.4 to 3.5 ; soluble in nitric acid, potash lye and 
ammonia. 

Asbestus. Fibrous. Color, green or white. The 
asbestus of commerce is practically a finely fibrous 
form of serpentine, that is to say, it is essentially a 
hydrated magnesium silicate. Every deposit of ser¬ 
pentine is a possible repository of asbestus. It 
occurs in seams half an inch to several inches in 
width, running parallel to or crossing one another, 
the width of each seam making the length of the 
fiber. Canada furnishes at present a large portion 
of the world’s supply of asbestus. The profitable 
mining, however, is at present confined to a small 


VARIOUS USEFUL MINERALS. 


253 


area in the great serpentine belt of the Province of 
Quebec, that lies to the south of the St. Lawrence 
River. In the form of a rough cloth, asbestus is 
used for covering steam-pipes and for many pur¬ 
poses requiring an incombustible material. 

Barytes, or barium sulphate , commonly called 
heavy spar, occurs in tabular, glassy crystals, and 
also in dull masses in veins of various rock forma¬ 
tions. Color, white or tinted; transparent or trans¬ 
lucent ; luster, vitreous or pearly. Specific gravity, 
4.3 to 4.7. Hardness, 3 to 3.5. It is readily dis¬ 
tinguished by its great comparative weight. When 
heated in the blowpipe flame splinters fly off the 
crystals. It fuses with difficulty, and imparts a 
green tinge to the flame. After fusion with soda, 
it stains a silver coin black. It is not acted upon 
by acids. 

In the United States barytes is found in many 
places, it being mined in Virginia, Missouri, New 
Jersey, and other states. It frequently occurs in 
connection with lead and zinc deposits, forming the 
gaugue of the metal-bearing vein. The best vari¬ 
eties of barytes are the white and gray. The chief 
use of barytes is as a pigment, as a cheap substitute 
for white lead. It is also used as a make-weight by 
paper manufacturers, etc. 

The carbonate of barium, witherite, is a much less 
common mineral than the sulphate. It sometimes 
occurs in crystals, but the more common form is 
that in fibrous masses. It occurs in veins. It fuses 
easily in the forceps, and gives a yellow-green flame. 


254 prospector’s field-book and guide. 

In hydrochloric acid it dissolves with efferves¬ 
cence, the solution yielding a heavy white precipi¬ 
tate (barium sulphate) if a little sulphuric acid is 
added. Witherite is used in the refining of sugar, 
and also in the manufacture of plate glass. 

Borax. Monoclinic. Hardness, 2 to 2.5 ; spe¬ 
cific gravity, 1.7. Fracture, conchoidal. Luster, 
vitreous to resinous. Color, white, sometimes gray¬ 
ish, bluish, or greenish. Streak, white. Taste, 
slightly alkaline and sweetish. Translucent to 
opaque. The occurrence of deposits of borax in 
the United States is, so far as known, limited to 
California, Nevada, and Oregon. In the early sev¬ 
enties, borax in large quantity and in a very pure 
condition was discovered on many of the alkaline 
marshes of western Nevada and eastern California. 
Refining plants were established and flourished for 
a time, but the increased production of borax in 
this country, together with the importation of large 
amounts from Italy, so reduced the price that in a 
few years most of the plants were abandoned. 

In 1890 it was found that the borax crust on most 
of the marshes is a secondary deposit, being derived 
from the leaching of beds of borate of lime in the 
Tertiary lake sediments that abound in the region. 
The marshes were abandoned and a mine was estab¬ 
lished on a bedded deposit at Borate near Daggett, 
San Bernandino County, California. The value of 
this deposit led to the discovery in Death Valley * of 

* Death Valley received its sinister name from the fact that, in 
1849, a band of emigrants wandered into the valley and most of 
them perished from thirst before an avenue of escape was discovered. 


VARIOUS USEFUL MINERALS. 


255 


enormous deposits that far exceed those now being 
worked near Daggett. 

The borax of Death Valley, as well as that near 
Daggett, occurs in a regular stratum, interbedded 
with the semi-inducted sands and clays that make 
up the bulk of the strata. These beds are gener¬ 
ally regarded as of Tertiary age, and they are sup¬ 
posed to have been deposited in inclosed bodies of 
water. 

The principal deposits of boron salts occurs at 
Borate near Daggett in the vicinity of the old Calico 
mining district. The mineral found here is borate 
of lime , or colemanite, and it occurs as a bedded de¬ 
posit from 5 to 30 feet in thickness, interstratified 
in lake sediments. These lake beds are composed 
of semi-indurated clays, sandstones and coarse con¬ 
glomerates with intercalated sheets of volcanic tuff 
and lava. The rocks are severely folded, the axes 
of the folds lying in an east-west direction. 

Borax is used in medicine and as an antiseptic 
by meat packers and others. Its chief use, how¬ 
ever, is as a flux in metallurgical operations, in 
enameling, glazing of pottery, and in the manufac¬ 
ture of glass. 

Clays. The clays are all products of alteration 
from other minerals. Their composition is variable 
and they do not crystallize. The true clays are all 
plastic and refractory to a greater or less degree, 
and on these properties their value for industrial 
purposes depends. Pure kaolin is the type of all 
the clays. 


256 prospector’s field-book and guide. 

The presence of alkalies in clays is objectionable, 
as it renders them fusible, as also do many other 
oxides. Iron is not only objectionable on the score 
of fusibility, but also as coloring matter. The 
presence of too large a proportion of water, carbonic 
acid or organic matter, causes clay to contract 
under the action of fire, and the same result will 
ensue if the clay is partially fusible. 

The soft clays are divided as follows : 

Kaolin , 'porcelain clay or China clay. This is a 
product of decomposition of feldspar and other min¬ 
erals, and never occurs in any crystalline form. Its 
composition varies somewhat according to the source 
from which it has been derived. In all cases it is a 
hydrated silicate of alumina, and its usual source is 
feldspar. It is a friable, soft substance of a white 
yellow, or flesh-red color, and capable of resisting 
the highest heat of a porcelain furnace. It usually 
contains more or less silica in an uncombined state. 
Its specific gravity is 2.2. Kaolin is almost entirely 
from the older feldspathic rocks, while clays are 
generally derived from younger rocks. 

Pottery or plastic clay is not so pure as kaolin, con¬ 
taining a large percentage of iron. 

Bole is a hydrated silicate of alumina and iron, 
of a somewhat variable composition, but generally 
containing about 42 per cent, of silica and 24 per 
cent, of water. It also contains a large amount of 
ferric oxide, which gives it its yellow-red or brown¬ 
ish-black color. It is soft and greasy, translucent 
or opaque, adheres to the tongue, and falls to pieces 


VARIOUS USEFUL MINERALS. 


257 


with a crackling noise when immersed in water. 
The hardness is 1.5 and the specific gravity 1.4 to 
2. It fuses with facility into a greenish enamel. 

Fuller's earth is a kind of clay composed, when 
pure, of 45 per cent, silica, 20 to 25 per cent, alum¬ 
ina, and water. It was formerly largely used as an 
absorbent in fulling or freeing woolen fabrics and 
cloth from fatty matters, but in modern times other 
substances have been substituted, and the consump¬ 
tion of it has greatly fallen off. 

Extensive deposits of Fuller’s earth occur in 
Decatur County, Georgia and in Gadsden, Leon 
and Alachua Counties, Florida. With the excep¬ 
tion of the Alachua County deposits, they are all of 
Upper Oligocene age, and equivalent with the Alum 
Buff beds. 

Coal (Mineral). Massive, uncrystalline. Color, 
black or brown ; opaque. Brittle or imperfectly 
sectile. Hardness, 0.5 to 2.5. Specific gravity, 1.2 
to 1.80. Coal is composed of carbon with some 
oxygen and hydrogen, more or less moisture, and 
traces also of nitrogen, besides some earthy material 
which constitutes the ash. 

The greater part of the coal formations originally 
consisted of peat or vegetable materials washed to¬ 
gether ; usually sand and clay were likewise con¬ 
tained in the deposit, and sometimes hydrated oxide 
of iron or ferrous carbonate. These deposits, in the 
course of time, with pressure, were formed into strata 
of alternate sandstone (usually gray) and slate clay 
or shale ; and between these strata, beds of brown or 
17 


258 prospector’s field-book and guide. 

black coal or anthracite and clay-ironstone were 
formed, subordinate, however, in extent and thick¬ 
ness to the sandstone, slate, and shale. Coarse con¬ 
glomerates, marl, or limestones very rarely occur 
in these formations. The Carboniferous period and 
the Tertiary period furnish the most characteristic 
examples of these formations, but the carbonaceous 
deposits of other periods are associated with similar 
rocks, and are so like the genuine coal formations 
that, petrographicall}', they are hardly to be distin¬ 
guished from them. 

Recent surveys, still incomplete, show that Alaska 
has coal in abundance and of the finest quality. 

Anthracite (Glance coal , Stone coal). Luster high, 
not resinous, sometimes submetallic. Color, gray- 
black. Hardness, 2 to 2.5. Specific gravity, if 
pure, 1.57 to 1.67. Fracture often concboidal. 
Anthracite consists almost entirely of carbon, and 
contains very little hydrogen, oxygen, or nitrogen. 
It contains earthy admixtures in various quantity. 
The normal position of anthracite appears to be in 
the transition formations. 

Bituminous coal. Color, black. Luster, usually 
somewhat resinous. Hardness, 1.5 to 2 ; specific 
gravity, 1.2 to 1.4. Contains usually 75 to 85 per 
cent, of carbon. 

Carmel coal. Very compact and even in texture, 
with little luster, and fracture largely concboidal. 

Brown coal (often called lignite). Color, black to 
brownish-black. Contains 52 to 65 per cent, of 
fixed carbon, 


VARIOUS USEFUL MINERALS. 259 

Jet resembles cannel coal, but is harder, of a 
deeper black and higher luster. It takes a brilliant 
polish and is set in jewelry. 

Dolomite is composed of carbonic acid, lime, 
magnesia. It occurs in rhombohedrons, faces often 
curved. It is frequently granular or massive: 
white or dull tinted ; and glassy or pearly. Specific 
gravity, 2.8 to 2.9 ; hardness, 3.5 to 4. Effervesces 
in nitric acid and dissolves more slowly than calc 
spar. Yields quicklime when burnt. Occurs in 
extensive beds of various ages like limestone. It is 
used as a building-stone and in the manufacture 
of Epsom salts. It is difficult to distinguish from 
calcite without chemical analysis. 

Feldspar, Orthoclase, is composed of silica, 
64.20 ; alumina, 18.40 ; potash or soda (lime), 16.95. 
Crystallized or in irregular masses. Opaque; 
usually flesh-red or white, or of various dull tints. 
Luster, glassy or pearly ; fracture, irregular, but in 
some directions it splits with an even, glimmering 
cleavage face. Specific gravity, 2.3 to 2.8 ; hardness, 
6. Before the blow-pipe it fuses with difficulty ; is 
not touched by acids. Where found in sufficient 
quantity to be of industrial value, it is usually ob¬ 
tained from veins in granite or pegmatite. The 
minerals associated with feldspar are chiefly quartz 
and mica: while tourmaline and topaz also occur 
commonly. Feldspar is, to a limited extent, em¬ 
ployed in the manufacture of glass, but the chief 
use for it is as a china glaze and as a glass-forming 
ingredient in the body of the porcelains. 


260 prospector’s field-book and guide. 

One of the finest varieties of feldspar is that 
known as Adularia, from Mount Adula, near the 
St. Gothard Pass, where it is found redeposited 
from the rock mass in veins and cavities. It con¬ 
sists of silica 64, alumina 20, lime 2, and potash 14. 
Moonstone is another variety, with bluish-white spots 
of a pearly luster. Sunstone is another, with a pale 
yellow color with minute scales of mica. Aventurine, 
feldspar sprinkled with iridescent spots from the 
presence of minute particles of titanium or iron. 
The last three varieties are employed as gem-stones, 
being occasionally set in brooches, but are too soft 
for rings. 

A beautiful variety of orthoclase known as Ama¬ 
zon stone occurs in large green crystals near Pike’s 
Peak, in Colorado, in Siberia and elsewhere. 

Flint consists of silica, which in a very fine con¬ 
dition has been separated from the surrounding 
rock, and which, attracted to some organic or inor¬ 
ganic nucleus, and sometimes only to itself, has 
grown in successive layers or bands, often of different 
colors. Hornstone or chert is allied to flint, but it is 
more brittle and it takes its color—dirty grey, red, 
and reddish-yellow, green or brown—from the rocks 
in which it is found. It occurs in portions of sand¬ 
stone rocks usually containing a little lime, the fine 
silica being seemingly collected into one spot. 

Fluorspar, Fluorite, consists of 48.7 per cent, 
of fluorine and 51.3 percent, of calcium. Its usual 
mode of occurrence is massive and granular. It is 
also found as cubic crystals in vuggs or coating the 


VARIOUS USEFUL MINERALS. 


261 


walls of small fractures in the country rock. It is 
generally translucent, though rarely transparent; 
its color is white or light violet, blue, purple, and 
occasionally yellow ; sometimes layers of different 
tints in the same piece. Luster, glassy. It breaks 
with smooth cleavage-planes parallel to the octa¬ 
hedral faces. Specific gravity, 3 to 3.2 ; hardness, 
4. Before the blowpipe it is fusible with difficulty 
to an enamel. It is used in the manufacture of hy¬ 
drofluoric acid, with which glass is etched, and also 
as a flux for copper and other ores. Sometimes it is 
employed for ornaments, especially massive pieces, 
they taking a high polish. It occurs in veins with 
lead and silver ores. 

Graphite, Plumbago, Blacklead, consists essen¬ 
tially of carbon, in mechanical admixture with 
varying proportions of siliceous matter, as clay, 
sand or limestone. It occurs in hexagonal crystals, 
but usually in foliated or massive layers. Color, 
steel-gray to bluish-black. Hardness very slight, 
0.5 to 1. Soils the fingers, makes a mark upon 
paper, and feels greasy. The specific gravities 
of different kinds of graphite vary according to the 
content of foreign admixtures, but lie within the 
limits of 2.105 and 2.5857. Graphite is not affected 
by acids and strongly resists other chemical agents. 
It is largely used in the manufacture of pencils, 
crucibles, stove polish, and lubricants for heavy 
machinery. It is found in various parts of the 
world, chiefly in crystalline limestone, in gneiss 
and mica schists, frequently replacing the mica in 


262 prospector’s field-book and guide. 

the latter so that they become actual graphite 
schists. Two distinct varieties are noticed : The 
one fine-grained, or amorphous; the other foliated, 
or compounded of numerous little scales; some¬ 
times also it appears as an impregnation of other 
rocks rather than as a distinct rock in itself. Geo¬ 
logically, it is confined to the oldest formations, and 
is usually, if not universally, associated with ineta- 
morphic action. The chief source whence the bulk 
of the mineral has for many years been derived is 
the Island of Ceylon. The soil and rocks of the 
island are almost everywhere impregnated with 
graphite, so that it may be seen covering the surface 
in the drains after a recent shower. The supply is 
practically inexhaustible, the mineral existing in 
such quantities in the gneiss rocks that, upon their 
decomposition, it is seen in bright silver-like specks 
throughout. Ceylon graphite is particularly re¬ 
markable for its purity, containing as it does very 
small proportions of siliceous ash. 

Graphitiferous rocks of the Laurentian system 
are widely spread throughout Canada and some 
parts of the United States. The graphite in these 
rocks usually occurs in beds and seams varying in 
thickness from a few inches to 2 to 3 feet. Perhaps 
the most important and extensive of the Canadian 
deposits is that near the township of Buckingham, 
where the graphite occurs both in beds or veins or 
disseminated. 

Considerable deposits of graphite are found in 
Chester County, Pennsylvania, Essex County, New 


VARIOUS USEFUL MINERALS. 


263 


York, and near Sonora, California. In the latter 
place the lode from which the mineral is obtained 
runs about 4,000 feet in a N. E. and S. W. direc¬ 
tion, and ranges from 29 to 40 feet in width. It is 
much broken up and mixed with the surrounding 
rock and earth to a depth of about 30 feet, but be¬ 
low this it is well defined between walls of sand¬ 
stone and clay-slate. The lode is frequently divided 
by lenticular masses of clay-slate, from a few inches 
to several feet in thickness. 

Close to the village of Ticonderoga, Essex Co., 
New York, graphite is obtained from a mountain, 
locally known as the Black-lead Mountain. The 
graphite, beds are interstratified between gneissic 
rocks. The beds dip at an angle of 45°. The ore 
in them is chiefly of the foliated variety, and is 
mixed with gneiss and quartz in the beds in veins 
or layers from 1 to 8 inches in thickness, some of 
the deposits being richer than others. One of these 
has been followed to a depth of 350 feet. It is 
found of varying thickness and it opens out at times 
into pockets. 

Graphite is said to occur in great purity in differ 
ent localities in Albany Co., Wyoming, in veins 
from 1 foot 6 inches to 5 feet thick. At Pilkin, 
Gunnison Co., it occurs massive in beds 2 feet thick, 
but of impure quality. It is also found in the coal 
measures of New Mexico, in Nevada, in Utah, and 
in the Black Hills of South Dakota. 

The value of graphite depends upon the amount 
of its carbon. To test the purity of graphite, pul- 


264 PROSPEOTOR ? S FIELD-BOOK AND GUIDE. 

verize and then dry at about 350° F. 20 grains of 
it; then place it in a tube of hard glass 4 to 5 inches 
long, half an inch wide, and closed on one end. 
Add twenty times as much dried oxide of lead and 
mix intimately. Weigh the tube and contents, and 
afterwards heat before the blow-pipe until the con¬ 
tents are completely fused and no longer evolve 
gases. Ten minutes will suffice for this. Allow 
the tube to cool, and weigh it. The loss in weight 
is carbonic acid. For every 28 parts of loss there 
must have been 12 of carbon. 

Gypsum is a hydrous sulphate of lime, and is 
composed of sulphuric acid, lime and water. It 
occurs in prisms with oblique terminations, some¬ 
times resembling an arrow-head. It is transparent 
or opaque, white or dull tinted, with a glassy, 
pearly or satin luster. Cleavage occurs easily in 
one direction ; specific gravity, 2.3 ; hardness, 2 ; can 
be readily cut with the knife. In the blow-pipe 
flame it becomes white and opaque without fusing, 
and can then be easily crumbled between the 
fingers. Nitric acid does not cause effervescence. 
It occurs in fissures and in stratified rocks, often 
forming extensive beds. When pure white it is 
called Alabaster ; when transparent, Selenite ; 
and when fibrous, Satin Spar. When burnt, 
gypsum loses its'water and falls to powder. This 
powder, called Plaster of Paris, which is per¬ 
fectly white when free from iron, possesses the 
property of reabsorbing the water lost, and in a 
very short time of assuming again the solid state, 


VARIOUS USEFUL MINERALS. 265 

expanding slightly in so doing. It is this last 
property that renders plaster of Paris so valuable 
for obtaining casts. It is also used as a fertilizer. 

Infusorial Earth is an earthy, sometimes chalk¬ 
like siliceous material, entirely or largely made up 
of the microscopic shells of the minute organisms 
called diatoms. It occurs in beds sometimes of great 
extent, sometimes beneath peat beds, and is ob¬ 
tained for commerce in Maine, New Hampshire, 
Massachusetts, Virginia, California, Nevada, Mis¬ 
souri. It feels harsh between the fingers and is of a 
white or grayish color, but often discolored by 
various impurities. Infusorial earth is used as a 
polishing powder, electro-silicon being the trade- 
name of one kind much used for polishing silver. 
It is also used for making soda silicate and for pur¬ 
poses of a cement. Being a bad conductor of heat, 
it is applied as a protection to steam boilers and 
pipes. It is also employed for filling soap. 

Lithographic Limestone. The only stone yet 
found possessing the necessary qualifications for 
lithographic work is a fine-grained homogeneous 
limestone, breaking with an imperfect shell-like or 
conchoidal fracture, and, as a rule, of a gray, drab 
or yellowish color. A good stone-must be suffi¬ 
ciently porous to absorb the greasy compound which 
holds the ink, soft enough to work readily under 
the engraver’s tool, yet not too soft, and must be 
firm in texture throughout and entirely free from 
all veins and inequalities. The best stone, and 
indeed the only one which has yet been found to 


266 prospector’s field-book and guide. 

fill satisfactorily all these requirements, occurs at 
Solenhofen, Bavaria. These beds are of Upper 
Jurassic age, and form a mass of some eighty feet 
in thickness. The prevailing tints of the stone are 
yellowish or drab. 

In the United States materials partaking of the 
nature of lithographic stone have been reported 
from various localities, but it is believed all have 
failed as a source of supply of the commercial 
article, though it is possible that ignorance as to 
the proper methods of quarrying may in some cases 
have been a cause of failure. 

Meerschaum or Sepiolite is a manganese sili¬ 
cate. When pure, it is very light; and, when dry, 
it will float upon water. It will be recognized by 
its property, when dry, of adhering to the tongue, 
and by its smooth, compact texture. It is generally 
found in serpentine, in which rock it occurs in 
nodular masses ; but it is also found in limestones 
of tertiary age. It is of a snowy-white color and 
a useful substance when found in quantity, being 
much employed for the bowls of tobacco pipes, and 
for this purpose is mined in Asia Minor. 

Micas. These are silicates of alumina with pot¬ 
ash, rarely soda or lithia, also magnesia, iron and 
some other elements. Always crystallized in thin 
plates, which may be split into extremely thin, 
flexible layers. Transparent in thin layers. Color, 
white, green, brown to black. Specific gravity, 2.7 
to 3.1. Hardness, 2 to 2.5 ; very easily scratched 
with a knife. Before the blowpipe mica whitens, 


VARIOUS USEFUL MINERALS. 267 

but is infusible except on thin edges. When it can 
be obtained in large sheets, it is very valuable. It 
is sometimes used in the place of window-glass on 
board ship, for stoves and for lamp-chimneys. The 
ground material is used as a lubricant and in mak¬ 
ing ornamental and fire-proof paint. 

Biotite , or black mica, contains more magnesia 
than alumina. It is often present in eruptive rocks, 
especially sonie granites. Muscovite, or white mica, 
on the contrary, contains more alumina than mag¬ 
nesia, and as it also contains potash in small, but 
appreciable, quantities, it is sometimes called potash 
mica , and biotite magnesian mica. Muscovite is an 
important mineral to the tin miner, since it is 
always found in that class of granite in which tin¬ 
stone occurs, and with quartz alone forms the rock 
called greisen , which is very generally associated 
with tin. The rock in which large sheets of mica 
are found is called by some geologists pegmatite, and 
has the same composition as granite itself, but the 
crystals are of a larger size. 

Nitre or Saltpetre is white, inodorous, not 
deliquescent; at a red heat it is decomposed with 
evolution, first of oxygen. It has a cooling saline 
taste, a vitreous luster, a hardness of 2, and specific 
gravity of 1.9. It is readily soluble in water. Be¬ 
fore the blowpipe it fuses easily on platinum wire, 
tinging the flame green. 

Nitre occurs as a separate formation in the cav¬ 
erns of several limestone mountains in Ceylon, 
Calabria and elsewhere, as an efflorescence from the 


268 prospector’s field-book and guide. 

surface on the ground, especially in hot weather 
after rain, also in springs. 

Chile saltpetre occurs in crystals and crystalline 
grains. Hardness, 1.5 to 2. Specific gravity, 2.1 to 
2.3. Colorless or light colored. Transparent to trans¬ 
lucent. Taste saline, cooling. Soluble in water; de¬ 
flagrates in glowing charcoal, but less vividly than 
niter. It fuses before the blow-pipe, tinging the flame 
yellow. It is found in grains mixed with the sand, 
and associated with gypsum, rock salt, and Glauber’s 
salt, occurring in many parts of the coast of Chile. 

Rock Salt has the character of ordinary table 
salt, but is more or less impure. Occurs in beds 
interstratified with sandstone and clays, which are 
usually of a red color and associated with gypsum. 
Specific gravity, 2 to 2.25, hardness 2 to 2.5. It 
contains 39.30 per cent, of sodium and 60.66 per 
cent, of chlorine, but most samples contain clay and 
a little lime and magnesia. The surface indications 
of rock salt are brine springs supporting a vegeta¬ 
tion like that near the seacoast, also occasional 
sinking of the soil caused by the removal of the 
subterranean bed of salt by spring water. Rock 
salt is obtained by sinking wells from which the 
brine is pumped and evaporated in large pans, or 
by mining, the same as foi: any other ore. 

Salt deposits occur in the strata of all ages, from 
the Silurian to those now forming. In North 
America a chain of mountains extends along the 
west bank of the river Missouri for a length of 80 
miles by 45 in breath, and of considerable height. 


VARIOUS USEFUL MINERALS. 


269 


These mountains consist largely of rock salt. The 
same formation extends into Kentucky, where the 
deposits are called “ licks,” because of the licking 
of the rocks and soil by the herds of wild cattle 
that once roamed there. In Michigan, in the 
neighborhood of Marine City, a well was sunk to a 
depth of 1,633 feet, when a deposit of rock salt was 
entered and penetrated to a depth of over 1,500 feet 
without the tools passing through it. The deposit 
seems to increase in thickness, but it is reached at 
an increasing depth as it trends in a southwesterly 
direction by Inverhuron, Kincardine, and Warwick. 

An extraordinary superficial deposit of rock salt 
occurs in Petite Anse Island, parish Iberia, Lou¬ 
isiana. The island is about two miles in diameter, 
and the salt deposit on it is known to extend under 
165 acres. It is covered with 16 feet of soil. It 
has been proved to a depth of 80 feet. The salt 
occurs in solid masses of pure crystals, and it is 
taken out by blasting. 

The bulk of the manufactured salt in North 
America is obtained from brine springs. Valuable 
and productive springs are worked in the Syracuse 
and Salina districts, New York, and in Ohio. Some 
of these arise from a red sandstone whose geological 
place is said to be below the coal measures. 

Rock salt has been discovered in Nevada. The 
southern termination of the deposits is about seven 
miles from the uppermost limit to the navigation 
of the Colorado river. Some of the specimens are 
sufficiently pure and transparent to allow of small 


270 prospector’s field-book and guide. 

print being read through them. In the same state 
there is an interesting salt lake, the water of which 
contains about two pounds of salt and soda to every 
gallon. It is several hundred feet deep. Soda and 
salt have been obtained from this lake for sev¬ 
eral years by natural evaporation. The water is 
pumped into tanks at the beginning of the summer 
season. It is left in these tanks during the warm 
summer months until the frost sets in. When the 
first frost comes the soda is precipitated in crystals. 
The water is then drained off into a large pond, 
where slow evaporation goes on, and a deposit 
of common salt is obtained. 

The famous salt mine of Wieliezka, near Cracow, 
in Galicia, has been worked since the year 1251, 
and it has still vast reserves of the mineral. 

Slate is an argillaceous shale easily recognized 
by its cleavability, and varies in color from light 
sea-green and gray to red, purple and black. It 
has been formed by sedimentary deposits, and now 
constitutes extensive beds in the Silurian formation. 

Sulphur. Native sulphur or brimstone occurs 
crystallized or massive in volcanic regions and in 
beds of gypsum. Color, yellow ; luster, resinous; 
specific gravity, 2.1 ; hardness, 1.5 to 2.5. It is 
fusible and burns with a blue flame and well-known 
odor. It is frequently found contaminated with 
clay or pitch. Italy and Sicily together furnish 
the greater part of the sulphur of commerce, the 
major portion coming from Sicily. The most im¬ 
portant deposits of brimstone in the United States 


VARIOUS USEFUL MINERALS. 


271 


are found in Utah at Cove Creek, 22 miles from 
Beaver, while there are other deposits at a point 
about 12 miles southwest from Frisco. Large de¬ 
posits of sulphur are known to exist in Wyoming, 
California and Arizona, but none of them is at 
present available for working at a profit. 

A scarcity of brimstone has led to greater atten¬ 
tion being paid to native pyrites, especially for the 
manufacture of sulphuric acid. While there are 
many deposits of iron pyrites in most parts of the 
world, they are not always accessible to mining at 
a low cost, and situated so that transportation of the 
low-valued product is easy and cheap. These pri¬ 
mary conditions are essential to the industrial useful¬ 
ness of any pyrites bed. The production of pyrites 
on a commercial scale in the United States is at 
present confined to Massachusetts and Virginia. 

Asa rapid and accurate method of estimating the 
sulphur available to the acid-maker in a sample of 
pyrites, J. Cuthbert Welch has published the fol¬ 
lowing in the Analyst: Place 5 grammes of pyrites 
in a porcelain boat in a combustion tube, heat to 
redness, pass oxygen* over till combustion is com¬ 
plete, and absorb the gas formed in about 30 cubic 
centimeters of a solution of bromine in a mixture of 
equal parts of hydrochloric acid (specific gravity, 

* The oxygen should be prepared from pure potassium chlorate 
in glass vessels, or at any rate in an iron one, kept especially for the 
purpose, and the gas should be passed through , a strong solution of 
potash in the bulbs, through a U-tube containing calcium chloride, 
and lastly, either through another calcium chloride tube or, prefer¬ 
ably, over phosphoric anhydride before use. 


272 prospector’s field-book and guide. 

1.1) and water, in potash (or preferably nitrogen) 
bulbs. Wash out the solution into a beaker, boil, 
precipitate by boiling solution of barium chloride, 
cool, filter and wash, dry and ignite the barium 
sulphate. 

Talc or Soapstone, called Steatite when mas¬ 
sive, is a hydrated silicate of magnesia, from which 
the water is only driven off at a high temperature. 
It usually occurs in foliated laminar masses, like 
mica, but differs from the latter in not being elastic, 
in being softer and readily marked by the nail, in 
yielding an unctuous-feeling powder, and in not 
containing alumina as an essential ingredient. The 
laminated variety of talc has been adopted by min¬ 
eralogists as representing 1 in the scale of hardness; 
its specific gravity is 2.7. The color is white, some¬ 
times tinged with green, and the luster pearly. 
When heated in a matrass, it undergoes no appre¬ 
ciable loss of water or transparency ; when subjected 
to a high heat it exfoliates and hardens, but does 
not melt. Acids have no effect upon it, either after 
or before ignition. Talc is quarried and employed 
for various purposes. It is mixed with clay to in¬ 
crease the translucency of the finished porcelain ; 
when powdered it is used for diminishing the fric¬ 
tion of machinery, and as a basis for colored cos¬ 
metic powders. Pencils are made from it for remov¬ 
ing grease from silks and cloths, and for marking 
out the patterns of clothes. 


CHAPTER XIV 


GEMS AND PRECIOUS STONES. 

Although many varieties of gems and precious 
stones are known to occur in the United States, 
systematic mining for them is carried on only at a 
few places, and the annual output is still very small 
in comparison with the prospective extent of the 
field. Not many persons are familiar with the ap¬ 
pearance of gem stones in their native state, so that 
while quartz pebbles are often mistaken for rough 
diamonds, garnets for rubies, ilmenite for black 
diamonds, etc., on the other hand it is quite prob¬ 
able that many valuable occurrences have escaped 
notice. 

Many of the gems are of comparatively little 
value, so that it is not always profitable to pay 
much attention to their discovery unless the quan¬ 
tity of them is great, for the cost of polishing is an 
important factor in assigning a value to them. 
Many colored transparent and translucent kinds of 
quartz colored by metallic oxides fall under this 
category. But it is so easy to prospect a stream, for 
instance, in a country of crystalline, igneous, or 
metamorphic rock, that a search for precious stones 
and gems of all kinds should be made much more 
frequently than is usually the case. With regard to 
18 (273 ) 


274 prospector’s field-book and guide. 

the precious varieties, it is well to bear in mind that 
the valuable specimens may be associated with all 
sorts of worthless specimens, all of which, though 
impure in quality, may really be sapphires, spinels, 
chr} r soberyls, tourmalines, zircons, etc. 

Though many are translucent rather than trans¬ 
parent, many dark in outward appearance, and all 
water-worn, more or less, and with surfaces not at 
all glass-like, and the majority not apparently trans¬ 
parent or translucent unless held up to the light, 
yet here and there a good specimen may be found. 
For all that, a knowledge of the general appearance 
of such impure specimens is probably of as much 
importance as that of the good ones, for the pros¬ 
pector who comes across them has an encourage¬ 
ment in his search for valuable ones. 

For some reason or other, diamonds and gold are 
often found in the same alluvial deposit, and aurif¬ 
erous beds should therefore be examined for this 
precious stone. The specific gravity of the diamond 
—higher than that of quartz or most pebbles—and 
that of gold are so very different that it does not 
follow that, for instance in a stream bed, these two 
minerals are always found close together. 

Whilst certain characteristics of precious stones, 
such as hardness and specific gravity, given in the 
table later on, may be useful to the prospector, yet 
it is not always an easy matter to distinguish a cer¬ 
tain precious stone from one which may be similar 
in appearance though perhaps of much less value. 
To assist any one in doubt, and in many instances 


GEMS AND PRECIOUS STONES. 


275 


to settle the point, the dichroiscope, Figs. G4 and 
65, is very useful, taking for granted that some 
practice with the various kinds of translucent or 


Fig. 64. 



EXAMINING A GEM THROUGH THE DICHROISCOPE. 


transparentjstones of various shades and colors has 
been acquired. The dichroiscope is in the shape 

Fig. 65. 



When a transparent or semi-transparent stone is examined through the 
dichroiscope, the color of the square A is different or of a shade different to 
that of the square B when dichroism exists. 

of a cylinder 2 inches long and 1 inch in diameter, 
and thus easily carried about. 

Placing by means of tweezers a translucent or 
transparent stone close to the one end of the instru¬ 
ment where the two square images are seen when 







276 prospector’s field-book and guide. 

the instrument, held skywards, is looked into, and 
turning it about in various directions, and at the 
same time turning the instrument round, the ob¬ 
server will notice whether the color of the two 
squares is one and the same. If the stone is amor¬ 
phous, such as flint, obsidian, etc., or crystallizing 
according to the cubic system, such as diamond, 
spinel ruby, garnet, etc., the two squares will be of 
the same color to that of the other when the colored 
stone is examined in certain directions, though it 
may be the same in certain others. 

Thus a true ruby, which affords two shades of 
pink, can be distinguished from a spinel ruby or 
garnet without dichroism, or from a pink tourma¬ 
line, which gives tw T o colors but somewhat differ¬ 
ently to those of ruby ; so, too, a sapphire, which 
gives a blue shade in one square, and a light shade 
of color without any shade of blue in the other, can 
be distinguished from an amethyst, which affords 
two shades of purple, or from a blue spinel, which 
does not show any twin coloration, or from an iolite 
(or water sapphire), in which the coloration is of its 
own kind. 

A tourmaline, either the green or brown variety, 
can be recognized directly by the color of the one 
square being quite dark compared to that of the 
other. 

An emerald affords two distinct shades of green 
(one bluish), easily remembered ; so a green garnet, 
which does not show twin colorations, cannot be 
mistaken for it, 


GEMS AND PRECIOUS STONES. 


277 


With the dichroiscope and two or three minerals, 
such as the sapphire, topaz and rock crystal to test 
for hardness and a little practice, and a slight 
knowledge of the crystallization of minerals which, 
though frequently found water-worn, not uncom¬ 
monly retain traces of the original crystal edges and 
faces, the prospector can examine his specimens 
with a very much easier mind than he would with¬ 
out them. Frequently neither the hardness of a 
gem stone nor its behavior before the dichroiscope 
is sufficient to enable its identity to be reliably 
known. In such a case its specific gravity may 
settle the question, but this may require a more ac¬ 
curate balance than the prospector may possess, and 
the advice of an expert may be necessary. 

Diamond. Diamonds are usually met with in 
alluvial soil, often on gold-diggings. In some In¬ 
dian fields a diamond-bearing conglomerate occurs 
which is made up of rounded stones cemented to¬ 
gether, and lies under two layers, the top one con¬ 
sisting of gravel, sand and loam, the bottom one of 
thick clay and mud. In the neighborhood of Pan- 
nah, between Sonar and the Son river, diamonds 
are found in ferriferous pebble conglomerate and in 
river alluvium. The most beautiful crystallized 
specimens are, however, found on the west side of 
the Nalla-Malla mountains, near Banganpally, be¬ 
tween Pennar and Kistnah, in a diamond-bearing 
layer between beds of primitive conglomerate. 

In Borneo the diamond is found associated with 
magnetic iron ore, gold and platinum, in alluvial 


278 prospector’s eield-boor and guide. 

deposits consisting of serpentine and quartz frag¬ 
ments as well as marl. 

In Brazil the province Minas Geraes is rich in 
diamonds, the most important occurrence being at 
Sao Joao do Barro, where they are found in an en¬ 
tirely weathered talcose slate. In other parts of the 
same country the diamond is also obtained from a 
conglomerate of white quartz, pebbles and light- 
colored sand, sometimes with yellow and blue quartz 
and iron sand. In the province of Bahia occurs a 
substance known as carbonado or black diamond. It 
is an allotropic form of carbon closely related to the 
diamond, and is found in small, irregular, crypto¬ 
crystalline masses of a dark gray or black color. 
Although its density is not so great as that of the 
diamond, it is very much harder ; in fact, it is the 
hardest substance known. A t first it was used only 
in cutting diamonds, but since the invention of the 
■core-drill for boring in rocks it has found a greatly 
extended use, and is now employed for the so-called 
“ diamond crown ” of this drill. The bort of the 
South African mines finds a similar industrial ap¬ 
plication, being worthless as a gem. 

In South Africa the diamond occurs associated 
chiefly with garnet and titanic iron ore, as well as 
with quartz opal, calcareous spar, and more rarely 
with iron pyrites, bronzite, smaragdite and vaalite. 
According to St. Meunier the South African dia¬ 
mond-bearing sands are composed of an exceedingly 
large number of constituents, eighty different varie¬ 
ties of minerals and rocks having been found in 


GEMS AND PREdOUS STONES. 


279 


them. Of minerals occur, for instance, diamond, 
topaz, garnet, bronzite, ilmenite, quartz, tremolite, 
asbestus, wallastonite, vaalite. zeolite, iron pyrites, 
brown iron ore, calcareous, spar, opal, hyalite, jasper, 
agate, clay. Of rocks are found, serpentine, eklo- 
gite, pegmatite and talcose slate. At the Kimberley 
mine, which more or less represents others in the 
neighborhood, the diamond-bearing ground forms a 
“pipe” or “ chimney ” surrounded by formations 
totally different from the payable rock. The en¬ 
casing material is made up of red sandy soil on the 
surface, underneath which is a layer of calcareous 
tufa, then yellow shale, then black shale, and below 
this, hard igneous rock. The diamond-bearing 
ground consists of “ yellow ground ” (really the de¬ 
composed “ blue ground ”), which is comparatively 
friable; and deeper down the “ blue ground ” 
(hydrous magnesian conglomerate), which needs 
blasting by dynamite. The “ blue ground ” is of a 
dark bluish to a greenish-gray color and has a 
more or less greasy feel. With it are mixed por¬ 
tions of boulders of various kinds of rock such as 
serpentine, quartzite, mica-schist, chlorite-schist, 
gneiss, granite, etc. All this “ blue ground ” has 
evidently been subjected to heat. The gems are in 
the matter which binds these rocks, not in the rocks 
themselves. 

Diamonds are also found in the Ural, various 
parts of Australia, New Zealand and in the United 
States. In the latter country diamonds have fre¬ 
quently been found since 1850, when the first one 


280 prospector’s field-book and guide. 

was discovered in the alluvial workings for gold in 
California. Since this time they have been found 
at intervals both in the recent alluvium and also in 
the ancient detritus covered by lava flows. The 
California localities include, in Amador Co., Vol¬ 
cano, where an association with garnet and chalce¬ 
dony is seen; Fiddletown, with gold and lead and 
copper ores; in Butte Co., the Cherokee ravine, 
with zircon, chromite, etc.; in Dorado Co., at Forest 
Hill. In North Carolina, at Brindletown Creek 
in Rutherford Co.; at Portis Mines, in Franklin 
Co., with gold in placer workings ; at Dysortville, in 
M’Dowell Co. Diamonds have also been found 
sparingly in Idaho and Oregon, and in Hall Co., 
Georgia. The garnet districts of Arizona and New 
Mexico may also be looked upon as favorable for 
the occurrence of this gem. One stone of 23} carats 
was found at Manchester, Virginia in 1855. It is 
of interest to note that much of the rock of North 
Carolina consists of a schistose rock, and that a flex¬ 
ible sandstone similar to the itacolumite of Brazil 
is also found. Many experienced geologists hold to 
the opinion that since so many associations of the 
diamond are present in North Carolina, they have 
hopes of their being eventually found there. In 
Wisconsin diamonds have been found in glacial de¬ 
posits with quartz, garnet, ilmenite and magnetite. 

The natural surface of the diamond is often un¬ 
equal ; its sides are lined, somewhat convex, and 
generally appear dulled, or as they are commonly 
called, rough, by the evident action of fire. The 


GEMS AND PRECIOUS STONES. 


281 


diamond breaks regularly into four principal cleav¬ 
ages. It does not sparkle in the rough, and the 
best test is its hardness and its becoming electric 
when rubbed before polishing. The color of the 
diamond varies through all tones of the color-scale, 
from absolute colorless through all shades of yellow, 
red, green, blue to intense black. Some colorless 
diamonds acquire on heating a reddish shade, which 
disappears on cooling. 

The occurrence of diamonds of different colors 
affords a remarkable illustration of what has been 
said about the colors of minerals. As pure carbon, 
diamond is colorless, as are also the microscopic 
diamonds artificially produced by an electric cur¬ 
rent, but in nature the stones are of different colors, 
which are imparted to them by a very small pro¬ 
portion of foreign matter. The yellow and gray 
tints decrease the value of the diamond, but red, 
blue and green varieties, on the contrary, are so 
rare that when diamonds are so colored their value 
is considerably greater than if perfectly colorless. 
For instance, the best blue diamond known is esti¬ 
mated at double the calculated value of a good 
colorless diamond of the same size. 

In Borneo a kind of black diamond is found 
which is very highly prized in consequence of its 
exceptional luster and rarity. It is even harder 
than the ordinary diamond. 

The specific gravity of the pure diamond varies 
from 3.5 to 3.6 ; that of the black diamond is from 
3.012 to 3.255. 


282 prospector's field-book and guide. 

One of the most beautiful qualities of the diamond 
is its power of refraction ; that of water is 0.785 ; 
that of the ruby, 0.739 ; that of the rock crystal, 
0.654 ; that of the diamond, 1.396. The refraction 
of the diamond is single in the entire crystals; when 
broken it possesses double, but imperfect, refraction 
in the thin layers. 

The value of the diamond is dependent on its 
color, its size, and the finish given to it by working. 
Perfectly colorless stones bring the highest price, 
and next, stones with a reddish, greenish and bluish 
shade, which, however, are quite rare. Yellowish 
diamonds are of less value, the price paid for them 
being the lower the more the yellow color plays into 
brown. 

Of the largest diamonds each has its own name 
and its own history. Of these may here be men¬ 
tioned the Koh-i-noor or mountain of light, Fig. 66, d. 

It passed from the Mogul Empire at the conquest 
of it by the Persians in 1739. Later it was in the 
possession of Runjeet King and, on the annexation 
of the Punjab it passed to the East India Company, 
by whom it was presented to Queen Victoria in 
1850. It originally weighed 186J carats, but was 
recut in 1852, and in its present state weighes 106-iV 
carats. 

The Orlof, Fig. 66, a , weighs 194f carats, and is 
as large as half a pigeon’s egg. It is claimed to 
have formed an eye for an idol in a Brahmin temple 
at Seringham, to have been stolen by a French 
soldier, and passed by the hands of an English sea 


GEMS AND PRECIOUS STONES. 


283 


captain to Amsterdam, where it was bought for 
Catherine II of Russia by Prince Orlof; it now 
adorns the Imperial sceptre of Russia. It has been 


Fig. 66. 



supposed that a diamond know as the Great Mogul 
was divided into three stones of which the Koh-i- 
noor and Orlof are two. This diamond is said to 
have weighed 560 to 787J carats in the rough ; it is 
not definitely known what became of it. 




284 prospector’s field-book and guide. 

The Grand Duke of Tuscany or Florentine , Fig. 66, 
b, is one of the most beautiful diamonds. It is a 
yellow diamond, and weighs 139f carats. It belongs 
to the House of Austria. The Pitt or Regent , Fig. 
66, c, is usually considered one of the finest and 
most perfectly cut stones in existence. It was found 
at the Partial Mines in India, and was bought by 
Governor Pitt for £20,400 ; later on it was bought 
by the French Regent for £80,000. It was stolen 
in 1792, but recovered, and still remains the prop¬ 
erty of the French nation. In the rough it weighed 
410 carats ; when cut it was 137 carats. The Hope 
diamond is of a rich sapphire blue with great fire 
and brilliancy. It weighs 44J carats. It is con¬ 
sidered an unlucky stone, and has seemed to pursue 
to misfortune or the grave those who have possessed 
it. It came mysteriously out of the East and was 
acquired by Louis XIV of France. The gem was 
still in the crown of France when Louis XVI died 
by the guillotine amid the storms of the great revo¬ 
lution. Then the jewel vanished for a time, and it 
was not until 1830, that a London dealer, purchas¬ 
ing it from a stranger, sold it to the banker Henry 
Thomas Hope. The Star of South Africa was found 
in 1869 in river diggings. In the rough it weighed 
83J carats ; cut as a brilliant it weighs 46J carats. 
The Victoria is also a South African stone ; its 
weight in the rough was 457J carats. In 1893 a 
stone 917f carats was found at the Jagersfontein 
Mine. From it a perfect brilliant of 239 carats was 
cut, and this is known as the Excelsior or Jubilee 


GEMS AND PRECIOUS STONES. 


285 


diamond. A stone of 655 carats was found at the 
same time in 1895. 

But by far exceeding all the specimens previously 
found is the diamond found at New Premier Mine, 
near Victoria, South Africa, January 25, 1905. It 
was found in the yellow ground, about 18 feet below 
the surface. It was named the Cullinan after the 
chairman of the Premier Company. Its weight is 
3,024f carats, and in size it may be roughly com¬ 
pared with a man’s tightly-clenched fist, its longest 
measurement being rather over four inches. This 
famous diamond has been presented to King Edward 
VII of England. 

Corundum. This mineral species includes some 
of the most important precious stones. The blue 
crystalline variety is called sapphire, the red, the 
ruby; the light-yellow Oriental topaz, the bright- 
green Oriental emerald, and the bright-violet Orien¬ 
tal amethyst. One variety exhibits a six-rayed star 
inside the prism, and is called the asterias. 

Considerable activity in corundum mining has 
sprung up within the last few years, and several 
new occurrences of corundum in quantity have been 
brought to light, those of special note being in On¬ 
tario, Canada, where the corundum occurs in a 
syenite, and in North Carolina and Georgia, where 
it occurs in a gneiss or a quartz-schist. 

The corundum localities in the United States are, 
with the exception of those in Montana, Colorado 
and California, limited to the Appalachian region, 
the mineral having been found at various points 


286 prospector’s field-book and guide. 

throughout nearly its entire length. The emery 
vein or bed at Chester, Mass., has furnished a large 
quantity of the mineral, but the chief American 
source is a narrow section of the southern portion of 
the Appalachian region extending from southwest¬ 
ern North Carolina into Georgia. 

Corundum was formerly regarded as occurring 
sparingly in nature, and in only a few types of 
of rocks, but it is now known to occur rather widely, 
and instead of being in quantity in the basic mag¬ 
nesium or periodite rocks only, it has been found 
in abundance in syenites, in gneisses and in schists. 
Although occurring in many of the crystalline rocks 
it has been observed as a rock constituent in only a 
few of them. In some cases it is an original con¬ 
stituent of the rock, and in other cases it has been 
formed later, during the process of metamorphism. 

Corundum, as it is mined for abrasive purposes, 
occurs as sand, crystal, or gravel, and block corun¬ 
dum. Sometimes all three types are found in the 
same deposit. The sand corundum consists of small 
grains or fragments of the mineral scattered through 
the vein. The crystal corundum consists of crystals 
up to three inches in length. The block variety 
often occurs in masses of almost pure corundum 
from 10 to 1000 pounds in weight. Again, it occurs 
in large masses intimately associated with horn¬ 
blende, feldspar, etc., making a rock which is tough 
and is difficult to work. Frequently, the only way 
to break the masses is to build fires over them, and 
then suddenly to cool them by pouring water upon 
them. 


GEMS AND PRECIOUS STONES. 


287 


It is the hardness of corundum which makes it 
of so great a value as an abrasive. Next to the 
diamond it is the hardest mineral known, having a 
hardness of 9 while the diamond has a hardness of 
10. Specific gravity 3.9 to 4.2. Luster, glassy, 
sometimes pearly. Fracture, uneven or conchoidal. 
Infusible before the blowpipe, and not affected by 
acids nor by heat. It is almost pure alumina con¬ 
taining but a small percentage of other consti¬ 
tuents, principally silica, water and ferric oxide. 

Emery is a granular impure form of corundum 
consisting of a mechanical admixture of corundum 
and magnetite or hematite. It is of great commer¬ 
cial value as an abrasive, though now carborundum 
is displacing it in this use to a large extent. Until 
recently the only emery known to occur in the 
United States was that at Chester, Mass., and Peek- 
skill, N. Y., but it has now been found in North 
Carolina in a very promising prospect. The chier 
foreign sources of emery are the Greek island of 
Naxos and Asiatic Turkey. 

Sapphire. This is the blue variety of corundum 
in its purest crystalline state. Its general composi¬ 
tion is alumina 92, silica 5.25, oxide of iron 1.0. 
The color most highly valued is a highly trans¬ 
parent bright Prussian blue. More frequently the 
color is pale blue, passing by paler shades into per¬ 
fectly colorless varieties. The paler varieties are 
frequently marked by dark blue spots and streaks 
which detract from their value. But these paler 
varieties lose their color when subjected to great 


288 prospector’s field-book and guide. 

heat, a fact which has some times been taken advan¬ 
tage of by unscrupulous dealers to pass them off as 
diamonds. 

The principal form of the sapphire is an acute 
rhomboid, but it has many modifications and 
varieties. On being broken it shows a conchoidal 
fracture, seldom a lamellar appearance. 

In the United States there are two areas of im¬ 
portance as producers of sapphires. One is the Cul- 
sagee Mine in Macon County, North Carolina, where 
the mineral occurs with spinel, tremolite, tourma¬ 
line, magnetite, rutile, chromite, olivine and mica, 
in gneiss. The other district is in Montana. 
Near Helena is a glacial moraine known as El 
Dorado Bar and in this sapphire has been found 
with topaz, garnet, cassiterite, quartz and cyanite. 
In addition it has been found in situ in Montana in 
a dyke with pyrope, at Yago Creek, near Judith 
River, of a fine corn-flower blue. At Santa Fe, 
New Mexico, in southern Colorado and Arizona, 
sapphires occur in the sand associated with peridot, 
pyrope and almandine garnet. 

Ruby. The ruby is the red variety of corundum 
and in composition varies from almost pure alumina 
to a compound containing 10 to 20 per cent, of 
magnesia, and always about 1 per cent, of oxide of 
iron. The ruby is subdivided into several varieties 
according to color, which in its turn is affected by 
mineral composition, spinel ruby occurring in bright 
red or scarlet crystals, rubicelle of an orange-red 
color, bala ruby rose red, almandine ruby violet, 


GEMS AND PRECIOUS STONES. 


289 


chlorospinel green, and pleonast is the name given to 
dark varieties. 

The crystals are usually small and when not 
defaced by friction they have a brilliant luster, as 
has also the lamellar structure, with natural joints 
which it shows on being broken. It exhibits vari¬ 
ous degrees of transparency. The color most valued 
is the intense blood red or carmine color of the 
spinel ruby. When the color is a lilac blue, the 
specimen was formerly known as the Oriental ame¬ 
thyst ,, and was regarded as a connecting link be¬ 
tween the ruby and the sapphire. In the United 
States ruby is found in various localities. It occurs 
in gneissic and metamorphic rocks and in granular 
limestone. In North Carolina ruby of gem quality 
is found at Corvee Creek, a tributary of the Little 
Tennessee River in a decomposed garnetiferous basic 
rock. Many much-weathered specimens have been 
found, which have led to the conclusion that rubies 
of very large size have been formed here. The 
associated minerals are garnet, spinel, monazite, 
rutile, ilmenite, different micas, staurolite, gold, 
etc., and the rubies often show inclusions sometimes 
so minute as to give the gem a “ sheen.” 

Ruby ranks above diamond in point of value for 
good stones of rich deep color. It has been stated 
that $100,000 has been paid for a very fine ruby 
of 38-^ carats. 

The garnet is sometimes mistaken for the East 
Indian ruby, which is the most precious variety, 
but the garnet is isometric , and cveq >vben Qut and 
19 


290 prospector’s field-book and guide. 

mounted may be distinguished from the oriental 
ruby by the superior hardness of the ruby, the 
latter being next to the diamond, while the garnet 
is only as hard as quartz, or not quite so hard, So 
that a garnet of the most precious kind if worn will, 
under the strong lens, show the lines of wear, 
especially on the edges, which are absent in the true 
oriental ruby. 

Topaz is composed of silica, alumina and fluorine. 
The fluorine may be detected before the blow-pipe 
in the open tube by powdering a little of the topaz 
and mixing it with a small quantity of microcosmic 
v salt (a salt of phosphorus). The heat of the blow¬ 
pipe will liberate the fluorine aud its strong pun¬ 
gent smell, as well as its corrosion of the tube will 
prove its presence. With the cobalt (nitrate) solu¬ 
tion on charcoal, it gives a fine blue color in proof 
of alumina. This is the best test of the topaz, as 
the color of the mineral is not always the same, nor 
is it always perfectly transparent. 

The topaz crystallizes in the orthorhombic section 
of the hexagonal or fourth system. The finest are 
generally in prismatic form, showing a flat plane at 
the extreme end, even when the end of the crystal 
has several inclined faces. The crystals break easily 
across with smooth brilliant cleavage. Transparent 
or semi-transparent. White, yellow, greenish, 
bluish, pink. Luster glassy, specific gravity, 3.5. 
Hardness, 8. Scratches quartz; is scratched by 
sapphire. Infusible, but often blistered and altered 
by heat. When smooth surfaces are rubbed on 


GEMS AND PRECIOUS STONES. 


291 


cloth they become strongly electric, and can attract 
small pieces of paper, but rough surfaces do not 
show this. The brilliant cleavage of topaz distin¬ 
guishes it from tourmaline and other minerals. 
Topaz occurs in gneiss or granite with tourmaline, 
mica, beryl ; also cassiterite or tin-stone, apatite, 
fluorite. The white topaz resembles the diamond, 
but unlike the latter it can be scratched by sapphire. 
The pale blue variety is of value for cutting into 
large stones for brooches; specimens are occasion¬ 
ally found of several pounds weight. Topaz of a 
beautiful sherry color occurs in Brazil. Specimens 
of this when heated become pink, when they are 
known as burnt topaz. The yellow varieties are 
cut as gems. Although not very valuable, they are 
quite brilliant and look very well. 

Topaz is usually found, when in situ , in attached 
crystals in cavities in granite. It is also frequently 
associated with beryl, tourmaline and feldspar. 
Topaz is resistent to most forms of weathering, 
and hence is often found in rolled pebbles in the 
detritus of granite and other rocks. 

In the United States, yellow crystals are found in 
Connecticut, blue ones in granite in Maine, color¬ 
less ones in Utah, and both colorless and pale blue 
occur with Amazon stone at Florissant in the Pike’s 
Peak district in Colorado. 

Beryl or Emerald is composed of silica, alumina 
and beryllium or glucinum. It is almost always 
found in distinct crystals, and usually in forms easy 
to recognize. The crystals are hexagonal prisms, 


292 prospector’s field-book and guide. 

usually green, transparent or opaque. Luster, 
glassy. Fracture, uneven. Specific gravity, 2.7. 
Hardness, 7 to 8. Infusible or nearly so, but 
becomes cloudy by heating. Occurs in granite rocks 
with feldspar and quartz. Valuable for jewelry 
when transparent and rich grass-green (emerald) or 
sea-green (aquamarine). 

Both emerald and aquamarine are found in 
Alexander Co., North Carolina. Green and golden 
beryl occur in Oxford Co., Maine, and beryl of a 
sapphire blue is found at Royalston in Massachu¬ 
setts. Emerald also occurs at Haddam in Con¬ 
necticut. In Colorado, on Mount Antero, very fine 
aquamarines are found associated with phenacite. 

A productive emerald mine is that of Muso, in 
New Granada, Mexico. The emerald occurs in 
veins and cavities in a black limestone that contains 
fossil ammonites. The limestone also contains 
within itself minute emeralds and an appreciable 
quantity of glucina. When first obtained the em¬ 
eralds from this mine are soft and fragile; the 
largest and finest emeralds could be reduced to 
powder by squeezing and rubbing them with the 
hand. After exposure to the air for a little time 
they become hard and fit for the jeweler’s use. 

Phenacite is a silicate of beryllium or glucinum. 
Its hardness is about the same as topaz, and its 
specific gravity 3.4 to 3.6. It occurs in glassy 
rhombohedral crystals, and its hardness, beautiful 
transparency and color make it valuable for cutting 
as a gem, since it is capable of extreme polish. 


GEMS AND PRECTOUS STONES. 


293 


Phenacite has been found at Pike’s Peak, Colorado, 
in crystals of sufficient size and quality to furnish 
fair gems. It also occurs at Topaz Butte with topaz 
and Amazon stone in granite ; also at Mount Artero, 
in Colorado with quartz and beryl. 

Zircon is composed of silica and zirconia. It is 
found in square prisms terminated by pyramids, 
and in octahedrons, but often also in pebbles and 
grains. Transparent or opaque. Wine or brown¬ 
ish red, gray, yellow, white. Luster, glassy ; frac¬ 
ture, usually irregular, but in one direction it can 
be split so as to exhibit a smooth even cleavage- 
face having an adamantine luster like the diamond. 
Specific gravity, 4.0 to 5.0 ; hardness, 7.5 ; scratches 
quartz, is scratched by topaz. Infusible ; the red 
varieties, when heated before the blow-pipe, emit a 
phosphorescent light, and become permanently col¬ 
orless. Zircon occurs in syenite, granite, basalt. 
In some regions it occurs in the rock so abundantly 
that when the rock has been worn down by the 
weather, it is left unaltered in considerable quanti¬ 
ties. It may then be obtained by washing the 
gravel in the manner of the gold miner. Clear 
crystals are used in jewelry, in jeweling watches, 
and imitation of diamond. It may be distinguished 
from the latter by its inferior hardness, and in not 
becoming so readily electric by friction. Fine 
crystals are obtained in New York and Canada; 
and good specimens also come from North Carolina 
and Colorado. 

Garnet is composed of silica, alumina, lime, 


294 prospector’s field-book and guide. 

iron, magnesia, manganese. It is found almost 
always in distinct crystals, and as these crystals are 
commonly isolated and scattered through the rock, 
it is not difficult to recognize them. The crystals 
are usually twelve-sided, having the form of a 
rhombic dodecahedron. They are transparent or 
opaque ; generally red ; also brown, green, yellow, 
black, white. Luster, glassy or resinous ; fracture 
conchoidal or uneven ; specific gravity, 3.5 to 4.3 ; 
hardness, 6.5 to 7.5 ; cannot be scratched with a 
knife. Fusible with more or less difficulty. Red 
varieties impart a green color to borax bead owing 
to presence of chromium. Garnet usually occurs in 
crystals scattered through granite, gneiss or mica- 
schist, also in crystalline limestone ; with serpen¬ 
tine or chromite; also in some volcanic rocks. Fine- 
colored transparent varieties (carbuncle, cinnamon 
stone, almandine) are used in jewelry. The garnets 
found in Arizona, New Mexico and Southern Colo¬ 
rado, and there called “ rubies,” are as fine as those 
from any other locality, the blood-red being the 
most desirable. Very fine crystals of cinnamon 
stone, cinnamon garnet or essonite have been found 
in New Hampshire, Maine, and at many other 
points in the United States. 

Tourmaline is composed of silica, alumina, mag¬ 
nesia, boracic acid, fluorine, oxides of iron (lime 
and alkalies). It is found in prisms with three, six 
nine or more sides, furrowed lengthwise, terminat¬ 
ing in low pyramids. Commonly black and opaque, 
rarely transparent, and of a rich red, yellow, or 


GEMS AND PRECIOUS STONES. 


295 


green color. Luster glassy ; fracture uneven ; spe¬ 
cific gravity, 3.1 ; hardness, 7 to 8 ; cannot be 
scratched with a knife. When the smooth side of 
a prism is rubbed on cloth it becomes electric and 
can attract a small piece of paper. Tourmaline 
occurs in granite and slate. Only the fine-colored 
transparent varieties, which are used as gems and 
for optical purposes, are of value. The principal 
source of tourmaline in the United States is the 
locality Mount Mica, at Paris, Maine. In Massa¬ 
chusetts, Chesterfield and Goshen yield good green 
tourmalines, and also a rose-red but opaque variety. 
Tourmaline is also found in New York. In Cali¬ 
fornia, at Mesa Grande, both the red and green 
varieties occur. 

Epidote is a silicate of alumina, iron and lime, 
but varies rather widely in composition, especially 
as regards the relative amounts of alumina and 
iron. It is usually found in prismatic crystals, 
often very slender and terminated at one end only ; 
they belong to the monoclinic system. Luster, 
vitreous; color, commonly green, although there 
are black and pink varieties. Epidote is found in 
many localities in the United States and in very 
large crystals ranging from brown to green in color, 
but as a rule the crystals are only translucent or 
semi-opaque, though some stones of considerable 
value and great beauty have been found in Rabun 
county, Georgia. 

Opal is composed of silica and water. It is never 
found in crystals; but only in massive and amorphous 


296 prospector’s field-book and guide. 

form. Fracture, conchoidal ; specific gravity, 2.2 ; 
hardness, 6 ; can be scratched by quartz and thus 
distinguished from it. It is infusible and generally 
milk-white. The most beautiful variety of opal is 
that called precious opal , which exhibits a beautiful 
play of colors and is a, valuable gem. One kind of 
precious opal with a bright red flash of light is 
called the^re opal, and another kind is the harle¬ 
quin opal. Common opal does not exhibit this play 
of colors, and it varies widely in color and appear¬ 
ance. Milk opal, as one variety is called, has a pure 
white color and milky opalescence, while resin opal 
or wax opal has a waxy luster and yellow color. 
Jasper opal is intermediate between jasper and opal; 
wood opal is petrified wood, in which the mineral 
material is opal instead of quartz. Opal is com¬ 
monly met with in seams of certain volcanic rocks; 
sometimes it occurs in limestone and also in metal¬ 
lic veins. Precious opal is rare in the United 
States, though some of high value is said to have 
been found in Creek Co., near John Davy’s River, 
Oregon. 

The precious opal found in Hungary occurs in 
fissures in a weathered andesitic lava with other 
forms of opal. Hungarian opals show the finest 
fire, and their colors deteriorate least with exposure. 

In Mexico precious opal occurs in the State of 
Queretaro in volcanic rock and associated with other 
forms of opal. The colors are intense, but in larger 
patches than the Hungarian specimens show, and 
the colors do not change so much when the stone is 
moved. 


GEMS AND PRECIOUS STONES. 297 

Turquois is a hydrated phosphate of aluminium, 
containing also a little copper phosphate, which is 
probably the source of the color, which in the most 
precious variety is robin’s-egg blue, and bluish- 
green in less highly prized varieties. It occurs only 
in compact massive forms, filling seams and cavi¬ 
ties in volcanic rock. Specific gravity 3.127. Tur¬ 
quois has been found in the Holy Cross mining 
region, thirty miles from Leadville, Colorado, and 
of late years a number of mines have been opened 
in New Mexico, at Los Carillos and in Grant 
County. The latter mines produce stones having a 
faint greenish tinge, which is either due to a partial 
change or metamorphism, which has taken place 
while the turquois was in the rock, or it may be a 
local peculiarity. Turquois occurs also in Arizona 
and at a point in Southern Nevada. At the latter 
place it is found in veins of small grains in a hard 
shaly sandstone. The color of this turquois is a 
rich blue, almost equal to the finest Persian, and 
the grains are so small that the sandstone is cut 
with the turquois in it, making a rich mottled stone 
for jewelry. 

Agate is found in almost every part of the world, 
and the difference of the constituent parts makes 
the specific gravity vary from 2.58 to 2.69. The 
agate, properly so called, is naturally translucent, 
less transparent than crystalline quartz, but yet 
less opaque than jasper. It is too hard to be even 
scratched by rock crystal. It takes a very good 
polish. It is never found in regular forms, but 


298 prospector’s field-book and guide. 

always either in nodules, in stalactites, or in irregu¬ 
lar masses Eye agates consist of those parts of the 
stone in which the cutting discovers circular bands 
of very small diameter arranged with regularity 
round one circular spot. These circles are fre¬ 
quently so perfect that they appear to be traced by 
the compass. The first round is white, the second, 
black, green, red, blue or yellow ; most rare are 
those whose circles are at equal distance from the 
center. Moss agate contains brown-black, moss-like, 
or dendritic forms distributed rather thickly through 
the mass. These forms consist of some metallic 
oxide (as of manganese). Of all the American 
stones used in jewelry there is no other of which so 
much is sold as the moss agate. The principal 
sources of supply are Utah, Colorado, Montana and 
Wyoming. 

Chalcedony is a semi-transparent variety of 
quartz of a waxy luster and varying in color from 
white through gray, green and yellow to browrn. 
It is translucent or semi-transparent. It occurs in 
stalactite, reniform or botryoidal masses which 
have been formed in cavities in greenstones and 
others of the older rocks. Into these cavities, as 
into miniature caverns, water-holding siliceous mat¬ 
ter has penetrated and deposited its solid contents, 
consisting almost exclusively of silica tinged by the 
presence of other minerals. Some of these cavities 
are several feet in diameter, and besides the color¬ 
ing of the encircling mass there are often, in the 
interior of the concretions in them, cavities or cen- 


GEMS AND PRECIOUS STONES. 


299 


tral nuclei which contain sometimes as many as 
twenty-four different substances, as silver, iron 
pyrites, rutile, magnetite, tremolite, mica, tourma¬ 
line, topaz, with water, naphtha, and atmospheric 
air. 

Carnelian is chalcedony colored by the oxide of 
iron hematite; it is sometimes called sard. It has 
the same properties as chalcedony and occurs either 
as an ordinary agate, or in fissures as vein agate. 
Although of wide distribution, only two localities, 
both in India, are known. The name carnelian 
was given to the stone on account of its flesh color. 

Chrysoprase is a variety of chalcedony colored 
green by oxide of nickel. In a warm dry place its 
color is destroyed, but it can again be restored by 
keeping it damp. 

Jasper is quartz rendered opaque by clay, iron 
and other impurities. It is of a red, yellow or green 
color. Sometimes the colors are arranged in rib¬ 
ands, or in other fantastic forms. It is used for 
ornamental work. 

Wood Jasper is a fossil wood silicified. It is 
found at Chalcedony Park, Arizona, and Yellow¬ 
stone Park. 

Bloodstone or Heliotrope is green jasper, with 
splashes of red resembling blood spots. 

Rock crystal is pure, transparent, colorless 
quartz, and is found at a great many localities in 
the United States. In Herkimer County, at Lake 
George, and throughout the adjacent regions in 
New York state, the calciferous sandstone contains 


300 prospector’s field-book and guide. 

single crystals, and at times cavities are found filled 
with doubly terminated crystals, often of remarkable 
perfection and brilliancy. These are collected, cut 
and, often uncut, are mounted in jewelry and sold 
under the name of “ Lake George diamonds.” 

Amethyst is a transparent variety of quartz of a 
rich violet or purple color due to the oxide of man¬ 
ganese which it contains. It crystallizes in the form 
of a hexagon, terminated at the two heads by a 
species of cone with six facets. These crystals are 
often in masses, and the base is always less colored 
than the top. Amethysts are generally found in 
metalliferous mountains, and are always in combi¬ 
nation with quartz and agate. They occur in many 
localities in the United States, for instance, near 
Greensboro, in North Carolina, and in the districts 
around Lake Superior, especially in the northwest, 
but not in so fine or large specimens as in Ceylon 
or Siberia. 

Rose quartz is pink, red, and inclining to violet- 
blue in color. It usually shows a vitreous luster, 
and small conchoidal fracture. It is as a rule not 
crystallized and but rarely transparent. It is liable 
to fade on exposure, though it may to some degree 
be restored by moistening the specimen. 

Yellow Quartz or Citrine or False Topaz 
occurs in light yellow translucent crystals. It much 
resembles yellow topaz in color, and hence is often 
called Occidental topaz or Spanish topaz. It is often 
set and sold for topaz, but may be distinguished 
from it by its want of cleavage and by being softer. 


GEMS AND PRECIOUS STONES. 301 

Smoky quartz or Cairngorm varies in color 
from a pale sherry tint through all degrees of smoky 
brown to almost black. It occurs in crystals iden¬ 
tical in all respects, except color, to rock crystal. Its 
commonest mode of occurrence is in fissures in gran¬ 
ite and allied rocks, sometimes in spaces in the outer 
parts of a granite mass, probably due to shrinkage on 
consolidation ; in such cavities sometimes associated 
with beryl, topaz and crystals of feldspar. 

Onyx and Sardonyx. A variety of quartz hav¬ 
ing a regular alternation of strata more or less even, 
and variously colored in black, white, brown, gray, 
yellow 7 and red. When the onyx has one or two 
strata of red carnelian, it is more valued and takes 
the name of sardonyx. In the onyx the dark strata 
are always opaque and contrast strongly with the 
clear, which, when thinned, become almost translu¬ 
cent. 

Cat’s Eye consists of a quartz mixed wdth parallel 
fibers of asbestus and amianthus. It is found in 
pebbles and in pieces more or less rounded ; it has a 
concave fracture ; is translucent and also transparent 
at the edges. It has a vitreous and resinous light. 
It is generally either green, red, yellow or gray. It 
marks glass. Its specific gravity is from 2.56 to 
2.73. When exposed to a great heat it loses luster 
and transparency, but does not melt under the blow¬ 
pipe unless reduced to minute fragments. 

Many other gem stones are known to occur in the 
United States, and the following list compiled by 
Mr. George F. Kunz * is here given : 

* Mineral Resources of the United States, Washington, 1883. 


302 prospector’s field-book and guide. 


List of gem stones known to 
Achroi'te (tourmaline). 

Agate (quartz). 

Agatized wood (quartz). 
Almandine (garnet). 

Amazon stone (microlene). 

Amber. 

Amethyst (quartz). 

Aquamarine (beryl). 

Asteria. 

Beryl. 

Bloodstone. 

Bowenite (serpentine). 

Cairngorm (quartz). 

Catlinite. 

Chalcedony (quartz). 

Chiastolite. 

Chlorastrolite. 

Chondroite. 

Chrysolite. 

Danburite. 

Diamond. 

Diopside (pyrozene). 

Elaeolite (nephelite). 

Emerald (beryl). 

Epidote. 

Essonite (garnet). 

F16che d’ amour (quartz). 
Fluorite. 

Fossil coral. 

Garnet. 

Grossularite (garnet). 

Heliotrope. 

Hematite. 

Hiddenite (spodumene). 
Hornblende in quartz. 

Idocrase. 

Indicolite (tourmaline). 

Iolite. 

Isopyre. 


occur in the United States. 

Jade. 

Jasper. 

Jet (mineral coal). 

Labradorite. 

Labrador spar (labradorite). 
Lake George diamonds (quartz). 
Lithia emeralds (spodumene). 
Made. 

Malachite. 

Moonstone (feldspar group). 
Moss agate (quartz). 

Novaculite (quartz). 

Obsidian. 

Olivine (chrysolite). 

Opalized wood (opal). 

Peridot (chrysolite). 

Phenakite. 

Prehnite. 

Pyrope (garnet). 

Quartz. 

Rhodonite. 

Rock crystal (quartz). 

Rose quartz (quartz). 

Ruby (corundum). 

Rubellite (tourmaline). 

Rutile. 

Rutile in quartz (quartz). 
Sagenite (quartz). 

Sapphire (corundum). 

Silicified wood (quartz). 

Smoky quartz (quartz). 

Smoky topaz (quartz). 

Spinel. 

Spodumene. 

Sunstone (feldspar). 

Thetis hair stone (quartz). 
Thomsonite. 

Tourmaline. 

Topaz. 



CHAPTER XV. 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 

Crude petroleum occurs only in the higher strata 
of rocks, it being never found in metamorphic rocks 
or crystalline formation. The Pennsylvania oil 
strata belong to the Devonian age, the anticlinal 
ridges being more favorable, it is said, than the syn¬ 
clinal ones. Sandstones saturated with oil form the 
reservoir, and this sandstone appears to be lenticu¬ 
lar in form, and of varying texture, sometimes pass¬ 
ing into conglomerates. The following facts appear 
to have been ascertained with reference to the Penn¬ 
sylvania oil region: 1. The thicker the cover the 
more the oil, large accumulations being seldom 
found under light covers. 2. The coarser and more 
open the sand the more the oil. 3. The sandstones 
buried in shales must form the reservoir. 4. Under¬ 
lying shales must exist which form the source of the 
oil. 

In the Ohio district the Trenton limestone which 
is struck at a depth at from 1,100 to 2,200 feet be¬ 
low the surface, and is covered by 400 to 1,000 feet 
of shales, appears to be both the producer and res¬ 
ervoir. The principal accumulation both of oil and 
gas, are always the uppermost beds of the limestones 
and generally not more than 20 or 30 feet below its 
(307 ) 


308 prospector’s field-book and guide. 

upper surface. The oil rock continues to a lower 
level but below the oil the rock is charged with 
brine containing unusual quantities of chloride of 
calcium and magnesium ; when this is struck the 
well is frequently lost, although it is sometimes pos¬ 
sible to plug it near the bottom. The limestone 
appears to be quite porous in parts, but this porosity 
seems to be due to dolomitization, the change hav¬ 
ing resulted in recrystallization, which has left in¬ 
numerable microscopic cavities, in which the oil has 
accumulated. 

In Kentucky petroleum occurs near the base of 
carboniferous limestone. In California it is found 
in strata belonging to the tertiary age, in Colorado 
and other western States, in those belonging to the 
cretaceous, and in North Carolina to those belonging 
to the triassic. In West Virginia it occurs in strata 
belonging to the coal measures. The Gulf Coastal 
Plain oil field of Texas includes a belt of country 
from 50 to 75 miles wide, bordering the Gulf of 
Mexico and extending from the vicinity of the Mis¬ 
sissippi River in Louisiana westward about two- 
thirds of the distance across Texas. The oil rock is 
a crystalline dolomitic limestone, having an ex¬ 
tremely porous structure; associated wfith it is con¬ 
siderable selenite or crystalline gypsum. Another 
abundant crystalline accessory mineral is native sul¬ 
phur. In'southwestern Alaska petroleum is known 
to occur at two localities—in the Enochkin Bay dis¬ 
trict and in the vicinity of Cold Bay. The Enoch- 
kin Bay oil seepages and so-called gas springs are in 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 309 

an area of shales and sandstones of Jurassic age, 
which are thrown up into a long anticline. At Cold 
Bay the rocks are chiefly Jurassic shales and sand¬ 
stones. 

Crude petroleum is a fluid of a dark color, 
sometimes black, and contains 84 to 88 per cent, 
of carbon, the rest hydrogen. 

In prospecting for petroleum, the prospector, be¬ 
sides the customary outfit, should carry a stick pro¬ 
vided with a long iron point. It is best to follow 
the courses of rivers and creeks upward, because the 
progress of the work will not then be impeded by 
the turbidity of the water. It is also advisable to 
make such excursions in the warm season of the 
year, because the oil exudes more freely at that time 
than in cooler weather, when especially heavy oils 
and mineral tar, or maltha, are readily converted 
into a butyraceous mass. It is also best to wait 
until the water in the rivers and creeks is low. 

Observe whether the surface of the water exhibits 
variegated iridescent figures, this being especially 
the casein places where the water stands quietly or 
moves very little, for instance, in coves. Such an 1 
iridescent film, when found, may be due to petro¬ 
leum, but also to iron oxides and similar substances. 
However, by touching the surface of the water, for 
instance, with the iron-pointed stick, a film of oxide 
of iron may be disintegrated in angular pieces and 
very small flakes, which can be moved in any direc¬ 
tion, while oil films, when separated, reunite, and 
can be readily distinguished from allied indications 


310 prospector’s field-book and guide. 

by the many changes in color and figures. To be 
sure, films of very heavy oil may occasionally be 
met with which can be separated into angular pieces, 
behaving in this respect like iron oxides, but they 
almost invariably exhibit variegated movable rings 
of color. In swamps other substances may produce 
a phenomenon similar to crude oil. 

When indications of oil have in this manner been 
discovered in a quiet part of a water-course, try to 
remove the iridescent film of the water-course, and 
turn up the bottom by several times driving the 
iron-pointed stick into it. If films of oil, together 
with bubbles of gas, reappear, and this phenomenon 
occurs regularly after repeated experiments, there 
may be an outcrop of oil which deserves further 
examination. 

However, if the work with the iron-pointed stick 
yields negative results, the oil must have floated 
down from above, and the examination of the water 
course has to be continued until by means of the 
iron-pointed stick the source of the traces of crude 
oil has been found. This source will usually be in 
sandstone or other porous rock, and pieces knocked 
off with a hammer will exhibit the oil generally in 
the form of drops, partly upon the surfaces of the 
strata and partly also in small cavities. Instead of 
petroleum, mineral tar—a black, smeary mass— 
will frequently be found. 

The rock itself is occasionally impregnated, which 
may be recognized partly by the odor and partly by 
the so-called water-test. For this purpose place a 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 311 

piece of the rock in quiet water, if possible exposed 
to the rays of the sun ; if the rock contains oil the 
characteristic iridescent colors appear, as a rule, 
upon the surface of the water. 

The fresh fracture of oil-bearing sandstone is, as 
a rule, of a darker color than that of adjoining rock. 

After rain, drops of water adhere to out-crops 
of oil sandstone in a manner similar to that observed 
on other fatty substances. 

If in prospecting in water-courses oil-bearing 
sandstone has been found, the question has to be 
answered whether the prospector has to deal with 
contiguous rock or simply with an erratic block. 
This question can, as a rule, be decided without 
much difficulty, from the position of the stratifica¬ 
tion and the petrographic character of the rock in 
question as compared with the surroundings. How¬ 
ever, if there is still a doubt, examine, by means of 
the water-test, the portions of rock in the natural 
continuation of the block. 

Should the oil-bearing rock actually turn out to 
be an erratic block, the rock from which it has been 
derived will be found above, either on the slopes or 
in the water-course itself. Knowing the petro¬ 
graphic character of the oil-bearing block, it will 
not be difficult to find in the neighborhood the rock 
from which it is derived. In the above-described 
manner the water-courses are traced to the limits 
of the territory. In carrying on the work of pros¬ 
pecting, it is advisable to examine specimens of all 
the sandstone by means of the water-test, since the 


312 prospector’s field-book and guide. 

latter frequently shows the presence of petroleum, 
though there may be no external indications of it. 

It may be mentioned that in cooler weather the 
traces of oil upon the surface of the water do not 
yield blue, red, yellow, etc., figures, or at least not 
very vivid ones, but a milky coloration, which 
possibly may also be due to other causes, so that 
determination is more difficult and less certain. 
This is another reason w T hy it is advisable to select 
warm days for prospecting. That oil may also be 
detected by its odor need scarcely be mentioned. 

In swampy puddles iridescent films, which do not 
consist of iron oxides, but of hydrocarbons formed 
by decomposition, are occasionally met with. If due 
to the latter cause, they do not reappear, or at least 
ouly to a slight extent when removed with the iron- 
pointed stick from the surface of the water. How¬ 
ever, in examining the bottom, gas-bubbles gener¬ 
ally rise to the surface. Such puddles are examined 
first in the centre, and then by detaching pieces 
from the edges with the iron-pointed stick. 

Salses (mud volcanoes), as well as abundant ex¬ 
halations of natural gas, if not derived from coal 
measures, are promising indications of the presence 
of petroleum in the territory. 

It need scarcely be mentioned that porous rock 
—if oil-bearing—justifies greater expectations than 
compact rock, and that larger quantities of oil may 
be looked for in oil-bearing sandstones of greater 
thickness. 

Although, generally speaking, a rich occurrence 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 313 

of oil may be inferred from abundant indications in 
the outcrop, the reverse is not always correct; in 
many oil-fields, now productive, the indications 
when first found were not especially encouraging. 

If the oil occurs in definite geological horizons, 
the latter must be particularly searched for and 
traced, and carefully examined in the water-courses 
crossing them, not only because the strata are there 
most denuded so as to allow of the best view of their 
geological structure, but also because the oil, since 
the restraining covering is wanting, has the best 
chance of exuding there, and the cut of the water¬ 
course is generally one of the lowest points of the 
outcrop, where the most abundant exudation takes 
place in consequence of the greater head of pressure. 

A very important question is whether the oil 
occurrs in beds or in veins. In answering this ques¬ 
tion the following particulars may serve as guiding 
points: 

With proportionately greater denudation of the 
oil-bearing rock, it is sometimes possible directly to 
decide this question by observation, whereby the 
prospector, however, must take into consideration 
that even with a bed-like occurrence the oil will 
collect in small fissures. With a vein-like occur¬ 
rence a fissure may be traced to where it assumes 
larger dimensions in the strike and dip. 

If the prospector has to deal with a thick seam or 
stratum of sandstone, recognized as oil-bearing, im¬ 
bedded in another rock, for instance, shale, such 
seam should be traced and pieces freshly cut from it 


314 prospector’s field-book and guide. 

examined as to their content of oil by the water-test. 
If positive results are obtained, it may be inferred 
that the sandstone is the bearer of the oil, and that 
it is a bed-like occurrence. 

In a large mass of sandstone several outcrops of 
oil may sometimes be found at quite a distance 
from each other. If in tracing the stratum of the 
first outcrop according to its strike, the second, 
third, etc., outcrops are encountered, we have to do 
with a bed-like occurrence. This tracing of the 
stratum is effected by means of a compass, however, 
always with due consideration to the configuration 
of the ground. Suppose the cross-section of the 
sandstone bed with the declivity—the so-called out¬ 
crop-line—construed and traced. The outcrop-line 
will deviate the more from the straight line of 
strike, the flatter the strata and declivities lie. In 
tracing the same stratum, it must be observed 
whether its strike does not change, which, of course 
will necessitate a change in the route of the pros¬ 
pector. 

If some promising outcrops of oil have been found, 
which will justify the execution of more extensive 
and more expensive prospecting work, it is advis¬ 
able to mark accurately in the sketch-map, in addi¬ 
tion to the outcrops, the relative heights, generally 
determined by an aneroid barometer, the strike and 
dip of the stratum reduced to the astronomical 
meridian, and the outcrops of well characterized 
concordant strata, for instance, imbedded in shale S, 
Fig. 61, no matter whether they lie in the upcast or 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 315 

downcast of the outcrops of oil, a. The relative 
heights of one of these strata are determined in 
several places, selecting points which can be readily 
found upon the map, and, if possible, lie at the same 
height, which can be readily effected without essen¬ 
tial error with the assistance of an aneroid barome- 


Fig. 61. 



ter by taking observations in rapid succession. The 
points of same height, for instance, 1 and 2, give 
the strike of the stratum for a greater distance. 

By connecting the outcrops of oil a by a line AA, 
and again determining in the latter several points 
of the same height, for instance, 3, 4 and 5, the 



316 prospector’s field-book and guide. 

general strike is again obtained. If the latter runs 
parallel with the general strike of the characteristic 
stratum S, previously traced, one is justified in in¬ 
ferring a bed-like occurrence of oil, even if the con¬ 
strued dip of the outcrop line of oil corresponds with 
the observed local dip of the strata. 

In these investigations it is presupposed that the 
oil is recognized as exuding from the solid rock, an 
error regarding the outcrop of it being, therefore, 
excluded. Such an error may, however, occur when 
the outcrop is covered with loose masses of earth 
and rock, to the base of which the oil exuding above 
flows down hidden, and escapes further below by 
some accidental cause. 

A vein-like occurrence of oil will not show the 
above-mentioned conformities with the characteristic 
concordant strata. Such an occurrence presupposes 
a fissure, which is generally connected with a throw 
of the strata. This is most frequently established 
by the fact that a characteristic stratum suddenly 
ends and does not reappear in its natural continua¬ 
tion but either to the right or left, or higher or 
lower. If two or more such points of disturbance 
have been found, their connecting line is the out¬ 
crop line of the fissure, Fig. 62. If this line passes 
through the outcrop a, or if several outcrops lie in 
it, a vein-like occurrence of oil must be inferred. 

However, sometimes the oil occurs in a maze of 
smaller and large fissures. This is shown in the 
construction by the fact that in the presence of sev¬ 
eral outcrops a linear distribution of the same can- 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 317 

not be recognized, and that the combinations yield 
the most varying results, according to whether ex¬ 
ploration is carried on from the one or the other 
outcrop. Such occurrence presents uncommon dif¬ 
ficulties in prospecting. 

It need scarcely be mentioned that in prospecting 
for oil, it is of great importance to hunt up and map 
the anticlinals and their saddles, as well as faults. 

The use of a contour map of an oil sand to locate 


Fig. 62. 



new pools in unprospected territory will materially 
aid the prospector, but cannot be absolutely relied 
upon, as the other conditions necessary for an ac¬ 
cumulation can only be learned by actual test. 

The directions here given for prospecting may 
have to be modified according to local conditions. 
With a sufficient preliminary knowledge of geology, 
any difficulties will, as a rule, be readily overcome 


318 prospector’s field-book and guide. 

by thoroughly digesting the principles of the direc¬ 
tions given. 

As regards the quality of the surface oil, it must 
be remembered that it is not a criterion for the oil 
occuring at greater depth. The oil thickens on 
the surface of the earth, and with increasing density 
becomes viscous and dark. If pale, limpid, and 
specifically lighter oil is found at the outcrop, it is 
sure evidence of oil of excellent quality at greater 
depth. In every case it may be expected that the 
quality of the oil at greater depth is superior to that 
at the outcrop. 

Ozocerite is a mineral paraffine or wax, and 
occurs generally in fissures and cavities in the 
neighborhood of coal-fields and deposits of rock salt, 
or under sandstone pervaded with bitumen. It is 
found in various localities in Africa, America, Asia 
and Europe. In the United States it occurs in 
Arizona, Texas and Utah. 

The most interesting deposit is in East Galicia, 
Austria. The ozocerite occurs there in a saliferous 
clay belonging to the miocene of the most recent 
tertiary period, and forming a narrow, almost con¬ 
tinuous strip on the northern edge of the Carpathian 
Mountains. This miocene group of saliferous clay 
consists chiefly of bluish and variegated clays, sands 
and sandstones, with numerous occurrences of gyp¬ 
sum, rock salt and salt springs. In Boryslaw, the 
strata of saliferous clay form a perceptible saddle as 
they sink on the south below the so-called menilite 
slates, which are very bituminous and foliated, and 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 319 

form here the most northern edge of the Carpathian 
Mountains. The principal deposit of ozocerite con¬ 
verges with the axis of the saddle as shown in Fig. 
63, S being the strata of saliferous clay, and M 
menilite slate. 

Closely allied to ozocerite are the following min¬ 
eral resins: 

Retinite, generally of a yellowish-brown, some- 
Fig. 63. 



times of a green-yellow or red color. It is found 
with brown coal in various localities. 

Elaterite or elastic bitumen, of a blackish- 
brown color, subtranslucent, and occuring in soft, 
flexible masses in the lead-veins of Castleton, in 
Derbyshire, in the bituminous sandstone of Wood¬ 
bury, Connecticut, etc. 

Pyropissite occurs in strata in brown coal. 

Ozocerite occurs in various shades of color, from 
pale yellow to black; when melted it generally 



320 prospector's field-book and guide. 

shows a dark-green color. The pale varieties are 
chiefly found in places containing much marsh gas. 
The dark-green, heavy variety is the best, while the 
black kind, or asphaltic wax, is the poorest; it con¬ 
tains resinous combinations of oxygen, and is inter¬ 
mediate between mineral oil and ozocerite. 

The odor of ozocerite is, according to its purity, 
agreeably wax-like. In consistency it is soft, pli¬ 
able, flexible to hard ; the mass in the latter case 
showing a conchoidal fracture, but softens on 
kneading. The boiling-point lies between 133° 
and 165° F., and of the so-called “ marble wax ” 
even as high as 230° F. The specific gravity is 
from 0.845 to 0.930. 

Ozocerite is readily soluble in oil of turpentine, 
petroleum, benzine, etc., and with difficulty in 
alcohol and ether ; it burns with a bright flame, 
generally leaving no residue. Its elementary com¬ 
position is about that of petroleum, 85 per cent, of 
carbon and 15 per cent, of hydrogen. 

Native Asphalt or Bitumen is solid at the ordi¬ 
nary temperature, of a black to blackish-brown 
color and a conchoidal facture with glassy luster. 
Hardness, 1 to 2 ; specifie gravity, 1 to 2. It melts 
at 90° F., and is very inflammable. It appears to 
be formed by the oxidation of the non-saturated 
hydrocarbides in petroleum. The most remarkable 
deposits are in Cuba, Trinidad and Venezuela. 
Other noted localities are the Dead Sea, Seyssel, 
(France), Dimmer, the Abruzzo, and Val de Travers. 
It occurs also of every degree of consistence, and in 


PETROLEUM, OZOCERITE, ASPHALT, PEAT. 321 

immense quantity, along the coast of the Gulf of 
Mexico, chiefly in the States of Tamaulipas, Vera 
Cruz and Tabasco, where not unfrequently it is as¬ 
sociated with rock salt and “ saltpeter.’’ It also 
occurs in Utah in widely-separated places. It has 
been found associated with ozocerite and more ex¬ 
tensively as melted out of sandstone. California 
includes a large area which furnishes asphalt, much 
the larger proportion being the product of the de¬ 
composition of petroleum, while the remainder 
occurs in veins that are evidently eruptive, the for¬ 
mer occuring in beds of greater or less extent on 
hillsides or gulch slopes, below springs of more 
fluid bitumen. These deposits are scattered over 
the country between the bay of Monterey and San 
Diego, but are chiefly observed west and south of 
the coast ranges, between Santa Barbara and the 
Soledad pass. Asphalt occurs also in other localities 
in the United States, for instance in Connecticut, in 
thin seams and veins in eruptive rock ; in New 
York in the region of eruptive and metamorphic 
rocks, in Tennessee in the Trenton limestone, etc. 
In some American specimens sulphur has been 
found to the extent of 10.85 per cent. Asphalt is 
in great request for paving purposes; it is of in¬ 
creasing value, and deposits are eagerly sought for. 

Peat. Peat is not a mineral, but consists of the 
cumulatively resolved fibrous parts of certain mosses 
and graminacese. It gradually darkens from brown 
to black with increasing age. It occurs in beds or 
in bogs. As a fuel it is most economically used at 
21 


322 prospector’s field-book and guide. 

the place where it is grown. Good peat yields about 
3 to 6 per cent, of tar proper, which is comparatively 
easy to purify by the usual method. 

The examination of a peat bog is very instructive 
with reference to the formation of coal as affording 
examples of vegetable matter in every stage of de¬ 
composition ; from that in which the organized 
structure is still clearly visible, to the black carbon¬ 
aceous mass which only requires consolidation by 
pressure in order to resemble a true coal. 


APPENDIX. 


PROSPECTING BY MEANS OF ELECTRICITY. 

Mr. Leon Draft and Mr. Alfred Williams have 
invented a method of finding ore by means of elec¬ 
tricity, by which they claim to be able to detect the 
presence of certain mineral ores invisible to the eye 
and undiscoverable by mining engineering. It is 
claimed that by this method not only can deposits 
be located, but that the extent and depth of the 
lode can be determined with an accuracy that is 
quite impossible with any existing system of pros¬ 
pecting. 

In working this method there are two stations, 
the transmitting and receiving. At the former 
there is a battery of 12 volts, giving 4 amperes and 
50 watts; a special form of break works in methyl¬ 
ated spirits, and is driven by a motor, which is 
supplied with current by a special local battery and 
a primary condenser. The current is next led 
through the primary by an inductor, a special form 
of induction coil having a large core and a very 
heavy winding on the secondary circuit. The cur¬ 
rent now passes through a secondary condenser to 
adjustable series and parallel spark-gaps. The elec¬ 
tric waves generated by this arrangement are taken 
(323) 


324 prospector’s field-book and guide. 

to earth by means of two iron spikes driven two to 
three inches into the ground. 

The receiving set comprises two similar iron 
spikes, driven into the ground to a depth of an inch 
or two, and connected up to a tripod on which are 
placed a series parallel and with a transformer and 
two delicate receivers or resonators. The inter¬ 
rupter breaks contact 700 times a minute. 

By adjusting his earth connections the operator 
can focus the waves on any field that he may wish 
to explore ; the lines of force travel outward and 
onward until they reach the iron spikes, in the re¬ 
ceiving set. When this occurs, the observer can by 
means of the resonators detect their presence by 
hearing the noise of the break, or by the sparking 
across the gaps. 

Now, in’a normal condition, i. e., if the ground 
be of a homogeneous character, the prospector 
should hear the noises loudest when exactly oppo¬ 
site the center of the base line of the transmitting 
station. 

The existence, however, of a vein or reef contain¬ 
ing metal has the tendency of throwing the waves 
out of normal course, by reason of the fact that it 
has a different conductivity from the material by 
which it is surrounded. The prospector must there¬ 
fore make his earth connections in different places, 
and shift his position until he can detect the pres¬ 
ence of the waves. When directly over the lode, 
the noise in the resonators will be loudest. 

Condenser-discharges from lodes manifest them- 


APPENDIX. 


325 


selves as overtones in the receivers, and at certain 
spots or nodal points the noise will cease altogether 
owing to the influence of the waves. 

The condenser-discharges can be heard over some 
lodes when the distance from the inductor is so great 
that the noise of the break or of the spark-gap can¬ 
not be heard ; thus they form a great assistance to 
prospecting, helping to determine not only the posi¬ 
tion and depth of a mineral deposit, but also, to a 
great extent, its nature and characteristics. 

The area to be energized by the electrical waves 
may be as small as 300 square feet and as large as 
30 square miles, and the terminals may be placed 
hundreds of yards apart. 

It will, of course, be necessary to train mining 
engineers and prospectors in the use of the instru¬ 
ments and in the detection of the presence of the 
waves. The whole outfit is, however, simple and 
easy to work with. Its development during the 
next few years will be watched with interest by all 
interested in mining operations. 

WEIGHTS AND MEASURES. 

British weights and measures, and those used in 
our country are based upon the weight of a cubic 
inch of distilled water at 62° Fah., and 30 inches 
height of the barometer, the maximum density. 
This was decided by Parliament, in the reign of 
George IV., to be 252.458 grains. Recent experi¬ 
ments, however, show that a cubic inch of water at 


326 prospector’s field-book and guide. 

the temperature of maximum density is 252.286 
standard grains. On this account scientists are 
urging the readjustment of the gallon, bushel, etc., 
but at present the tables below are correct. See also 
No. 8. 

Weights and measures of various nations :— 


No. 1.— English Length. 


3 barleycorns 
12 inches 

3 feet 
5£ yards 

4 poles or 100 links 
10 chains 

8 furlongs 


- 1 inch. 

= 1 foot. 

= 1 yard. 

- 1 rod, pole, or perch (16£ feet). 

= 1 chain (22 yards or 66 feet). 

= 1 furlong (220 yards or 660 feet). 

= 1 mile (1760 yards or 5280 feet). 

A span = 9 inches ; a fathom = 6 feet; a league = 3 miles; a 
geographical mile = 6082.66 feet, same as nautical knot, 60 being a 
degree, i. e., 69.121 miles. 


Particular Measures of Length, 


A point, of an inch. 
A line, y 1 ^ of an inch. 
A palm, 3 inches. 

A hand, 4 inches. 

A link, 7.92 inches. 


A pace, military, 2 feet, 6 inches. 
A pace, geometrical, 5 feet. 

A cable’s length, 120 fathoms. 

A degree (average), 69& miles. 


No. 2.— Surface Measure. 


144 square inches 
9 square feet 
30^ square yards 
16 poles (square) 

40 poles 

10 chains or 4 roods 
640 acres 


1 square foot. 

1 square yard. 

1 pole, rod, or perch (square). 
1 chain (sq.) or 484 sq. yds. 

1 rood (sq.) or 1210 sq. yds. 

1 acre (4840 sq. yds.). 

1 sq. mile. 


APPENDIX. 


327 


No. 3.—Surface 

9 square feet 
272£ “ 

4,356 “ 

10,890 “ “ 

43,560 “ “ 

27,878,400 “ 


Measure in Feet. 

= 1 square yard. 

= 1 pole, rod, or perch. 
= 1 square chain. 

= 1 square rood. 

= 1 acre. 

= 1 square mile. 


No. 4.—Solid Measure. 

1728 cubic inches = 1 cubic foot. 

27 cubic feet =* 1 cubic yard. 

16£ feet long, 1 foot high, and feet thick = 1 perch stone = 
24f cubic feet. 


No. 5.—Troy Weight. 

Platinum, gold, silver, and some precious stones 
are weighed by Troy weight, diamonds by carats 
of 4 grains each. 


24 grains 

= 

1 pennyweight. 

20 pennyweights 

= 

1 ounce (480 grains). 

12 ounces 

= 

1 pound (5760 grains). 

No. 6.- 

-Avoirdupois Weight. 

16 drams 

= 

1 ounce (437£ grains). 

16 ounces 

= 

1 pound (7000 grains). 

14 ponnds 

= 

1 stone. 

2 stones 

= 

1 quarter. 

4 quarters 

= 

1 hundredweight. 

20 hundred-weight 

= 

1 ton (long ton) (2240 pounds). 


No. 7.—Weight by Specific Gravity. 

Frequently the weight of masses is required 
where it it very inconvenient, or, perhaps, impos¬ 
sible to use scales. The following method may be 
sufficiently accurate:— 


328 PROSPECTORS FIELD-BOOK AND GUIDE. 

Find the average specific gravity of the.mass 
either by actual weight of a piece or by the follow¬ 
ing table. Then measure the cubic contents of the 
mass as nearly as possible and multiply by the 
weight of a cubic foot. Thus, a mass of limestone 
(as good marble) measures 40 cubic feet. The 
specific gravity of good marble is 2.6, that is, it is 
2.6 as heavy as a cubic foot of water, which weighs 
62.5 pounds. Therefore 62.5 

2.6 

3750 

1250 

162.50 

A cubic foot of good marble weighs 162.5 pounds 
and the 40 cubic feet will weigh 162.5 

40 

6500.0 

or, about 3J tons. Of course, all rock masses have 
not plane sides, and the irregularity requires some 
calculation, and various allowances which the pros¬ 
pector must make, and can easily do with a little 
consideration. 

When greater accuracy of specific gravity and of 
bulk is desired for small masses, and no scales are 
at hand, the following plan may be very satisfac¬ 
torily adopted. Fill a tub or hogshead or large box 
with rain water, after having inserted a tube or 
piece of tin pipe into the upper edge. Pour in more 





APPENDIX. 


329 


water until it will hold no more without running 
out of the spout. Introduce the mass of rock and 
catch all the water which runs out of the pipe. 
Now measure the overflow; this represents the 
exact cubic measure of the rock introduced. 

1 gallon contains .... 231 cubic inches. 

1 quart “ . . .87.75 or 57f cubic inches. 

1 pint “ .... 28.87 or 28f “ 

1 gill “ .... 7.21 or 7} “ “ 

See Appendix , No. 8. 

Suppose the overflow was 8 gallons, 1 quart, 1J 
gills, and that the specific gravity of the rock or ore 
was 6.5 by the table below. Then the mass will 
cause an overflow of 1936.99 cubic inches, and this 
is 208.99 more than one cubic foot, or about 1.120 
of a cubic foot for the mass. 

Since 6.5 was the specific gravity of the ore, 
6.5X62.5 pounds = 406.25, which would be the 
weight of a cubic foot of the ore, and 406.25Xl.120 
=455 pounds, the exact weight of the mass you 
introduced into the water. 

No. 8—Special Weights, etc. 

One cubic foot of water is equal to 7.475 U. S. 
gals, of 231 cubic inches each, or 7J gallons nearly; 
or 6.2321 imperial gals, of 277J cubic inches each. 
This, with what follows, is important in the con¬ 
struction of tanks, pools, etc., where contents, 
weight, and pressure are to be considered. 

It should be remembered that, although the Eng- 


330 prospector’s field-book and guide. 


lish imperial gallon is 277J cubic inches = 10 lbs. 
avoir, of distilled water at 62° Fab., bar. 30 inches, 
and equal to 277.274 cubic inches, the United States 
standard gallon is 231 inches, or 58372.1754 grains, 
or 8.3389 lbs. of distilled water maximum density. 
This is almost exactly = to a cylinder 7 inches 
diameter, 6 inches high. The beer gallon = 282 
inches. 

One gallon = 8.3389 lbs., one quart = 2.0847 
lbs.; one pint = 1.0423 lbs.; one gill = 0.2606 lb., 
U. S. standard measure. One cubic foot of water 
=62.310 lbs., British weight; recent and correct, 
62.278. 


No. 9. —French Measures.—Length. 


Millimetre of a metre) = 

Centimetre ( T ^ u “ ) = 
Decimetre “ “ ) = 

Metre (the unit of length) = 
Decametre (10 metres) = 
Hectometre (10C metres) = 
Kilometre (1000 metres) = 
Myriametre (10,000 metres) = 


.03937 inch. 

.3937 “ 

3.937 

39.3708 “ or 3.2S09 ft. 

32.809 ft. or 10.9363 yds. 
109.3633 yards. 

1093.63 yds. or .62138 mile. 
6.2138 miles. 


Surface. 


Centiare (y 1 ^ of an are or sq. metre) = 
Are (unit of surface) = 

Decare (10 ares) = 

Hectare (100 ares) = 


{ 

{ 

{ 


1.1960 sq. yds. 
119.6033 sq. yards or 
.0247 acre. 
119(3.033 sq. yards or 
.2474 acre. 

11960 33 sq. yards or 
2.4736 acres. 


APPENDIX. 


331 


Solid Measure. 


Decistere ( x \ of a stere) — 
Stere (cubic metre) = 

Decastere (10 steres) ==. 


3.5317 cubic feet. 
35.3166 “ “ 

353.1658 “ “ 


W EIGHT. 


Milligramme (toVtf °f a gramme) = .0154 grain. 


Centigramme ( T ^ u 
Decigramme (y 1 ^ “ ‘ 

Gramme (unit of weight) 
Decagramme (10 grammes) 


) = .1544 grain. 

) = 1.544 grains. 
= 15.44 grains. 
= 154.4 grains. 


Hectogramme (100 u ) 


= 1,544 grains. 


f 3.2167 ozs. 

! Tr °y ° r 

j 3.5291 ozs. 
Avoir. 


Kilogramme (1000 “ ) 32£ ozs. or 2.2057 pounds. 

Myriagramme (10,000 grammes) = 22.057 pounds. 


No. 10. —Specific Gravity of Metals, 
Ores, Rocks, etc. 


Platinum .... 

Gold. 

Mercury. 

Lead. 

Silver. 

Copper. 

Iron when pure*.. 
Iron, cast, average 


16-21 

16-19.5 

13.5 

11.35-11.5 
10 . 1 - 11.1 
8.5-8.9 
7.78 

6.7; foundry 6.9 to 7 


Ores : associated with gold and silver. 


(Gold) Iron pyrites. 4.8-5.2 

Copper pyrites. 4.0-4.3 

(Silver) Galena. 7.2-7.7 

Glance (silver).7.2-7.4 

Ruby silver (dark). 5.7-5.9 

“ (light).5.5-5.6 

Brittle silver (sulphide).S.2-6.3 

Horn silver. .5.5-5.6 


















332 prospector’s field-book and guide. 


Other Ores. 

Zinc blende. 3.7-4.2 

Mercury (Cinnabar). 8.8-9.9 

Tin, tinstone, cassiterite. 6.4-7.6 

Tin pyrites ••• . 4.3-4.5 

Copper—Red or ruby copper. 5.7-6.15 

Gray.... ...... .... 5.5—5.8 

Black oxide. 5.2-6.3 

Pyrites. 4.1-4.3 

Carbonate (Malachite). 3.5-4.1 

Lead—Sulphide (Galena). 7.2-7.7 

Carbonate (White lead). 6.4-6.6 

Zinc-Blende. 3.7-4.2 

Calamine. 4.0-4.5 

Iron—Hematite (red). 4.5-5.3 

Magnetic.%. 4.9-5.9 

Brown hematite. 3.6-4.0 

Spathic (carbonate). 3.7-3.9 

Pyrites (mundic). 4.8-5.2 

Antimony—Gray sulphide. 4.5-4.7 

Nickel—Kupfer nickel. 7.3-7.5 

Cobalt—Tin-white. 6.5-7.2 

Glance. 6.0 

Pyrites. 4.8-5.0 

Bloom. 2.91-2.95 

Earthy. 3.15-3.29 

Manganese—Black oxide. 4.7-5.0 

Wad, Bog manganese. 2.0-4.6 

Bismuth—Sulphide .. 6.4-6.6 

Oxide. 4.3 

Minerals of Common Occurrence. 

Quartz. 2.5-2.8 

Fluorspar. 3.0-3.3 

Calc spar. 2.5-2.8 

Barytes.. 4.3-4.8 

® ranite t. 2.4-2.7 

Gneiss ' 

Mica slate. 2.6-2.9 





































APPENDIX. 


333 


Syenite ... 

Greenstone trap. 

Basalt . 

Porphyry . 

Talcose slate. 

Clay slate. 

Chloritic slate. . 

Serpentine . 

Limestone and Dolomite. 

Sandstones . 

Shale. 

Other minerals are mentioned in the text with 
gravities. 


• 2.7-3.0 
. 2.7-3.0 
. 2.6-3.1 
. 2.3-2.7 
. 2 . 6 - 2.8 
. 2.5-2.8 

• 2.7-2.8 

• 2.5-2.7 

• 2 5-2.9 
. 1.9-2.7 
. 2.8 

their specific 


No. 11. —A Ton Weight of the Following will 
Average in Cubic Feet : 


Earth 21 cubic feet. 

Clay 18 “ “ 

Chalk 14 “ “ 

Coarse gravel 19 “ u 


Pit sand 22 cubic feet. 
River sand 19 “ “ 

Marl 18 “ 

Shingle 23 “ “ 


Assay of Gold by the Touchstone.* 

This is a rough and rapid method of approxi¬ 
mately ascertaining the quality of a gold alloy 
without injury to the article, as is the case in dry 
and wet assaying. 

An experienced person may determine the correct 
standard within 1 per cent, of the truth. The 
method is based on the fact that the richer an alloy 
is in gold, the more clearly does a streak drawn with 
it on a black ground exhibit a pure golden-yellow 
color, and the less it is attacked by a test acid. 

The touchstone is a hard siliceous stone of a black 
color, its surface being prepared and left so that it 

* From Idioms’s Practical Metallurgy and Assaying.” 













334 prospector’s field-book and guide. 

will just abrade the metal from any sharp angle of 
the alloy when the latter is drawn over the stone. 

In order to ascertain the quality of the alloy, its 
streak is compared with streaks drawn by alloys of 
known fineness, called touch needles , of which five 
series are required. 

1. Red series , consisting of gold and copper, the 
gold increasing by half carats in successive needles. 

2. White series , contains gold and silver. 

3. Mixed series , in which the quantities of silver 
and copper alloyed with the gold are equal. 

4. Unequal mixed series, in which the silver is to 
the gold as 2 :1. 

5. Series in which the silver is to the copper as 

1 : 2. 

Besides these, special needles are prepared for 
different kinds of work. 

The mark left on the stone by the alloy having 
been matched with the corresponding mark of one 
of the touch needles, it is assumed to have the same 
composition. To confirm this assumption, a drop 
of acid is placed on each streak, allowed to work for 
some time, and its effect observed in each case, then 
wiped off to see if the mark is left unchanged. 

The test acid consists of: 98 parts pure nitric acid, 
2 parts hydrochloric acid, 25 parts distilled water. 

The first streak made by a body is discarded, as 
in the case of colored gold, for example, the surface 
having a different composition to the general mass. 

The above test mixture has no effect on alloys of 
18 carats and upwards, so that streaks made by 


APPENDIX. 


335 


these alleys will not be wiped off with a linen rag 
after treating with acid. Pure nitric acid has no 
effect on alloys of 15 carats upwards. 

Estimation of Gold in Alloys (Hiorns). 

In places where a large number of assays have to 
be conducted a special set of weights is employed, 
as with silver, the unit quantity being termed the 
assay pound, which is subdivided into carats, carat 
grains, eights, and excess grains. The amount 
taken as a unit may be 10 grains or half a gramme 
= 7.716 grains. The relation of the parts are 
well shown in the following table by Prof. Roberts- 
Austen : 






Excess 

Grains. 

Decimal 

Equiva¬ 

lent. 




Eights. 

1 

.1730 



Carat 

Grains. 

1 

7.5 

1.3021 ' 


Carats. 

1 

8 

00 

10.410 

Assay 

Pound. 

1 

4 

32 

210 

41.0 

1 

21 

90 

70S 

5700 

1000. 






















336 prospector’s field-book and guide. 

The excess grains in one assay pound are the 
same as the number of grains in the troy pounds. 

Gold is reported to the trade according to the 
above table, in carats or the decimal equivalents. 
Thus pure gold is 24 carats or 1000 fine; standard 

gold, 22 carats = —= 916.66 fine. 

When an alloy is slightly “ worse ” than the 
standard, it is said to be “worse so much.” When 
above the standard, the alloy is called “ better so 
much,” the difference being expressed in carat 
grains, eights, and excess grains, or in its decimal 
equivalent. In both cases the excess grains repre¬ 
sent gold present in excess of the report. 


Standard Values of Gold in Different 
Countries. 


Countries, 

1OO0 

(24 carats). 

916.66 
(22 carats). 

900 

(21.6 carats). 

England.\ 

(one troy ounce) j 

£4 4 10 

£3 17 10 

£3 16 6 

United States.( 

(one troy ounce) I 

$20.67 

$18.95 

$18.60 

France (Kilogramme).. 

Fr. 3,444.44 

Fr. 3,157.40 

Fr. 3,100 

Germany “ 

Mk. 2,790 

Mk. 2,474.16 

Mk. 2,511 


Power for Mills. 

As the Pel ton wheel seems to find the most fre¬ 
quent application in California, it may be conveni¬ 
ent to have the following rule, applicable to this 
wheel: 












APPENDIX. 


337 


When the head of water is known in feet, multi¬ 
ply it by 0.0024147, and the product is the horse¬ 
power obtainable from one miner’s inch of water. 
The power necessary for different mill parts is: 


For each 850 lbs. stamp, dropping 6 inches 95 times per 

minute. 1.33 H. P. 

For each 750 lbs. stamp, dropping 6 inches 95 times per 

minute. 1.18 “ 

For each 650 lbs. stamp, dropping 6 inches 95 times per 

minute. 1.00 “ 

For an 8-inch by 10-inch Blake pattern rock-breaker.. 9.00 “ 

For a Frue or Triumph vanner with 220 revolutions 

per minute. 0.50 “ 

For a 4-foot clean-up pan, making 30 revolutions per 

minute ....**•• . 1.50 “ 

For an amalgamating barrel, making 30 revolutions 

per minnte. •••• . 2.50 “ 

For a mechanical batea, making 30 revolutions per 

minute. 1.00 “ 


Boring. 

Rock is bored with jumpers of 10 to 18 lbs., used 
alone or with boring bars and hammer. The 
former are more effective, but can only be used 
perpendicularly, or nearly so, and with rock of 
moderate hardness; they require more skill. 


18 lb. hammers are used for 3 inch boring bars. 

• 16 lb. “ “ “ inch boring bars. 

14 lb. 11 “ “ 2 and If inch boring bars. 

5 to 7 lb. “ “ “1 inch boring bars. 

The boring bars may be made of 1^-inch bar 
iron of various lengths, with steel bits up to 3 
inches. A bit should bore from 18 to 24 feet with 
22 









338 prospector’s field-book and guide. 


each steeling, and requires to be sharpened once for 
every foot bored. 


Diamond Drill. 

This drill is applicable to sinking a bore-hole for 
prospecting for minerals or water, shafts, etc., or 
blasting under water. 

It consists of a circular row of “carbonados,” a 
species of diamond, set in a circular steel ring. 
This is attached to a hollow steel tube, which is 
kept rotating at about 250 revolutions per minute, 
pressed forward by a force varying from 400 to 800 
lbs., according to the nature of the rock. Water is 
supplied through the tube, which washes out the 
debris and cools the diamonds. 

Granite and the hardest limestones are penetrated 
at the rate of 2 or 3 inches per minute, sandstones 
4 inches, quartz 1 inch. 

The diamond drill is not effective in soft strata, 
such as clay, sand and alluvial deposits. 


APPENDIX. 


339 


The Chemical Elements, their Symbols, Atomic 
Weights* and Specific Gravities. 


Name. 


Aluminium. 

Antimony. 

Arsenic. 

Barium. 

Bismuth. . 

Boron. 

Bromine. 

Cadmium. 

Caesium. 

Calcium. 

Carbon... 

Cerium. 

Chlorine. 

Chromium. 

Cobalt. 

Columbium. 

Copper . 

Didymium. 

Erbium. 

Fiuorine. 

Gallium. 

Glucinum. 

Gold (Aurum). 

Hydrogen . 

Indium. 

Iodine . 

Iridium .... 

Iron (Ferrum). 

Lanthanum. 

Lead (Plumbum). 

Lithium. 

Magnesium. 

Manganese. 

Mercury (Hydrargyrum) .... 

Molybdenum. 

Nickel . 

Niobium. 


Symbol. 

Atomic 

Weight. 

Specific 

Gravity. 

Al. 

27.5 

2.56 

Sb. 

120.4 

6.70 

As. 

75.0 

5.70 

Ba. 

137.4 

4.00 

Bi. 

208.1 

9.7 

B. 

11.0 

2.63 

Br. 

79.95 

5.54 

Cd. 

112.4 

8.60 

Cs. 

132.9 

1.88 

Ca. 

40.1 

1.58 

C. 

12.0 

3.50 

Ce. 

139.0 

6.68 

Cl. 

35.5 

2.45 

Cr. 

52.1 

6.81 

Co. 

59.0 

7.7 

Cb. 

184.8 

6.00 

Cu. 

93.7 

8.96 

Hi. 

96.0 

6.54 

E. 

166 0 

— 

F. 

19.05 

1.32 

Ga. 

70.0 

5.9 

Gl. 

9.5 

2.1 

Au. 

197.2 

19.3 

H. 

1.008 

0.069 

In. 

114.0 

7.4 

I. 

126.85 

4.94 

Ir. 

193.1 

21.15 

Fe. 

55.9 

7.79 

La. 

138.6 

11.37 

Pb. 

206.92 

11.44 

Li. 

7.03 

0.59 

Mg. 

24.3 

1.75 

Mn. 

55.0 

8.01 

Hg. 

20 .0 

13.59 

Mb. 

96.0 

8.60 

Ni. 

58.70 

8.60 

Nb. 

93.7 

6.27 


* According to the Committee of the American Chemical Society 
(Clarke). 

























































340 prospector’s field-book and guide. 


The Chemical Elements, their Symbols, Equiva¬ 
lents and Specific Gravities. 


Name. 

Symbol. 

Atomic 

Weight. 

Specific 

Gravity.' 

Nitrogen. 

N. ' 

14.04 

0.972 

Osmium. 

Os. 

191.0 

21.40 „ 

Oxvgen. 

0. 

16.0 

1.105 

Palladium. 

Pd. 

107.0 

11.60 

Phosphorus. 

P. 

31.0 

1.83 

Platinum. 

Pt. 

194.9 

21.53 

Potassium (Kalium) . 

K. 

39.11 

0.865 ] 

Rhodium . 

Ro. 

103.0 

12.1 

Rubidium *. 

Rb. 

85.4 

1.52 - 

Ruthenium. 

Ru. 

101.7 

11.4 

Selenium . 

Se. 

79.2 

4.78 

Silicon . 

Si. 

28.4 

2.49 

Silver (Argentum). 

Ag. 

107.92 

10.5 

Sodium (Natrium). 

Na. 

23.05 

0.972 

Strontium. 

Sr. 

87.6 

2.54 

Sulphur. 

Tantalium . 

S. 

32.07 

2.05 

Ta. 

1828 

10.78 

Tellurium. 

Te. 

127.5? 

6.02 

Thallium. 

Tl. 

204.15 

11.91 

Thorium... 

Th. 

232.6 

7.8 

Tin (Stannum). 

Sn. 

119.0 

7.28 

Titanium . 

Ti. 

48.15 

4.3 

Tungsten (Wolfram). 

W. 

184.0 

17.6 

Uranium. 

U. 

239.6 

18.4 

Vanadium . 

V. 

51.4 

5.50 

Yttrium. 

Y. 

89.0 

— 

Zinc. 

Zn. 

65.4 

7.14 

Zirconium. . 

Zr. 

80.4 

4.15 


The figures indicating the proportions by weight 
in which the elements unite with one another are 
called the combining or atomic weights, because they 
represent the relative weights of the atoms of the 
different elements. Since hydrogen is the lightest 
element, it is taken as the standard, and its combin¬ 
ing or atomic weight = 1. 










































APPENDIX. 


341 


To find the 'proportional parts by weight of the ele¬ 
ments of any substance whose chemical formula is 
known: 

Rule.— Multiply together the equivalent and the 
exponent of each element of the compound ; the 
product will be the proportion by weight of that 
element in the substance. 

Example .—Find the proportionate weight of the 
elements of alcohol, C 2 H 6 0 : 

Carbon C 2 = equivalent 12 X exponent 2 = 24 
Hydrogen H 6 = equivalent 1 X exponent 6 — 6 
Oxygen O = equivalent 16 X exponent 1 — 16 


Of every 46 lbs. of alcohol, 6 lbs. will be II ; 16 
O ; 24 C. 

To find the proportions by volume , divide by the 
specific gravity. 


Common Names of Chemical Substances. 


Caustic potash. 

Chloroform. 

Common salt. 

Copperas and green vitriol. 
Corrosive sublimate. 

Dry alum. 


Common Names. 
Aqua fortis. 

Aqua regia 
Blue vitriol. 

Cream of tartar. 
Calomel. 

Chalk. 


Chemical Names. 

Nitric acid. 

Nitro-hydrochloric acid. 

Sulphate of copper. 

Bitartrate of potassium. 

Chloride of mercury. 

Carbonate of calcium. 

Hydrate of potassium. 

Chloride of formyl. 

Chloride of sodium. 

Sulphate of iron. 

Bichloride of mercury. 

Sulphate of aluminium and potas- 


Epsom salts. 


sium. 

Sulphate of magnesium. 



342 prospector’s field-book and guide. 


Ethiops mineral. 

Galena. 

Glauber’s salt. 

Glucose. 

Iron pyrites. 

Jeweler’s putty. 

King’s yeltow. 

Laughing gas. 

Lime. 

Lunar caustic. 

Mosaic gold. 

Muriate of lime. 

Muriatic acid. 

Nitre or saltpetre. 

Oil of vitriol. 

Potash. 

Realgar. 

Red lead. 

Rust of iron. 

Sal ammoniac. 

Salt of tartar. 

Slaked lime. 

Soda. 

Spirits of hartshorn. 
Spirits of salt. 

Stucco or plaster of Paris. 
Sugar of lead. 

Verdigris. 

Vermilion. 

Vinegar. 

Volatile alkali. 

Water. 

White precipitate. 

White vitriol. 


Black sulphide of mercury. 
Sulphate of lead. 

Sulphate of sodium. 

Grape sugar. 

Bisulphide of iron. 

Oxide of tin. 

Sulphide of arsenic. 
Protoxide of nitrogen. 
Oxide of calcium. 

Nitrate of silver. 
Bisulphide of tin. 

Chloride of calcium. 
Hydrochloric acid. 

Nitrate of potash. 
Sulphuric acid. 

Oxide of potassium. 
Sulphide of arsenic. 

Oxide of lead. 

Oxide of iron. 

Chloride of ammonium. 
Carbonate of potassium. 
Hydrate of calcium. 

Oxide of sodium. 

Ammonia. 

Hydrochloric acid. 
Sulphate of lime. 

Acetate of lead. 

Basic acetate of copper. 
Sulphide of mercury. 
Acetic acid (diluted). 
Ammonia. 

Oxide of hydrogen. 
Ammoniated mercury. 
Sulphate of zinc. 


APPENDIX. 


343 


PROSPECTORS’ POINTERS. 

OLD-TIMER INSTRUCTS THE TENDERFOOT PROSPECTOR 
ON LOCATING. 

Take a soft pine board, and a hard lead pencil, 
and the writing will sometimes outlast your claim. 
I have seen such notices that have withstood the 
storms of seven or eight years and still remain 
legible. There is a great variety of ways to write 
a notice; and nearly every prospector has his own 
way. But the briefest and most concise way is as 
good as any, and the easiest. Now, I’ll write you 
one for the Catharine this way: 

Catharine Lode. 

Notice is hereby given that I, the undersigned 
citizen of the United States, having complied with 
Chapter 36, Title 32, Revised Statutes of the United 
States, and the local regulations of Barker district, 
claim by right of discovery, 1500 feet in length, and 
600 feet in width, along the mineral-bearing vein, 
to be known as the Catharine (or any other name). 

Beginning at centre of discovery shaft and run¬ 
ning : “ How far do you run northerly ? ” 

“ Seven hundred feet northeast.” 

“ Seven hundred feet in a northerly direction and 
800 feet in a southerly direction. 

“ Always say northerly, southerly, easterly, and 
westerly in writing notices. Don’t give it any spe¬ 
cific direction. When you say ‘ northerly,’ it gives 
you a chance to swing your stakes all round the 


344 prospector’s field-book and guide. 

North Pole, if necessary. You can swing your 
stakes after your location is made any way you 
want to, provided there are no conflicting claims, 
unless you change from northerly and southerly to 
easterly and westerly, or vice versa. In that case, 
you have to make an amended location and record 
it. Let’s see. Where were we ? Oh, yes ; together 
with 300 feet on either side of the vein. 

“ Located this 18th day of June, 1891.” 

“ Locator— Tenderfoot, Prospector.” 

Now that is all that is necessary to hold any 
claim, as far as the notice goes. Some prospectors 
put in a claim for all dips, spurs, angles, and varia¬ 
tions throughout the width, breadth and depth of 
the claim; but that’s all foolishness. The law 
grants you all the spurs and angles and dips you 
want. You just go ahead and do as the law re¬ 
quires you to do, to hold any mining claim.”— 
Butte Bystander . 


INDEX 


A cids, 12 

Actinolite, 7 
Adamantine luster, 21 
Adularia, 260 

Africa, diamonds in, 278, 279 
Agate, 3, 297, 298 
Alabaster, 265 
Alaska, gold product of, 113 

methods of recovering gold 
in, 123-125 
petroleum in, 308, 309 
stream tin in, 195, 196 
Albite, 4, 5 

Alloys, estimation of gold in, 335, 
336 

Alluvial claims, estimating the 
value of, 51 

deposits, estimation of, 47-49 
forms of, 49-51 
minerals occurring in, 54 
gold fields, cement of, 128, 
129 

Almaden, Spain, quicksilver de¬ 
posits at, 222 
Alum, 249 

Alumina, detection of, 87 
Aluminite, 239 
Aluminium, 239-242 

antimony, manganese, 239- 
248 

Amalgamating assay of gold, ISO- 
132 

Amalgams, native, 221 
Amazon stone, 260 
Amethyst, 3, 300 
Amphibole, 7, 8 
Amygdolite, 31 
Analysis of ores, 86-111 

for nickel and co¬ 
balt, 228-236 
qualitative, 89 
wet method of, 89-101 


Andesite, 5 
Anglesite, 187 
Anorthic feldspars, 4 
Anorthite, 5 
Anthracite, 258 
Antimonite, 242, 243, 244 
Antimony, 242 

detection of, 87, 100, 101 
glance, 242, 243, 244 
ore, assay of, 110 
Apatite, 249-251 
Aquamarine, 292 
Aqueous rocks, 33 
Areas, to measure, 79-82 
Argentiferous minerals, 161, 162 
Argentite, 157, 158 
Arsenic, 251, 252 
detection of, 86 
native, 251 
testing for, 100 
Arsenical pyrites, 209, 210 
Asbestus, 8, 252, 253 
Asbolite, 238 
Asphalt, native, 320, 321 
Assay, amalgamating, of gold, 
130-132 
definition of, 59 
dry, of ores, 101-111 
furnace, 102, 103 
of gold by the touchstone, 
333-335 
tin ore, 192 
ton weights, 104, 105 
Assaying gold quartz, 108, 109 
Asterias, 285 
Augite, 8-10 
Auriferous lodes, 44, 45 

quartz, rule for ascertaining 
the amount of gold in a 
lump of, 146, 147 
Aventurine, 260 
Avoirdupois weight, 327 


( 365 ) 





366 


INDEX. 


Azoic rock, 27 
Azurite, 175, 176 

B ANCA, discovery of tin in, 
194 

Barium sulphate, 253, 254 
Barytes, 253, 254 
Basalt, 31 
Bases, 12 
Batea, 117 
Bauxite, 240, 241 
Beach placers, 51 
Beds and layers, 42 
Beryl, 291, 292 

Billiton, discovery of tin in, 194 
Biotite, 6, 35, 267 
Bismuth, 224 

detection of, 99 
gold, 114 
Bitumen, 320, 321 
Bituminous coal, 258 
Black band ore, 208 
gold, 114 
jack, 201, 202 
lead, 261-264 
mica, 267 

oxide of copper, 175 
tellurium, 149 
Bloodstone, 299 
Blow-pipe and its use, 56-68 
construction of a, 62, 63 
cupelling, 186 
experiments, 63-67 
means of chemically testing 
minerals before the, 63 
mode of using the, 58, 59 
practice, requirements for, 57 
Blowing, practice of, 59 
Blue carbonate of copper, 175, 
176 

flame, 59 
Blueite, 227 
Bole, 256, 257 
Borate of lime, 255 
Borax, 57, 58, 254, 255 
Boring, 337, 338 
bars, 337 

Borneo, diamonds in, 277, 278 
Bornite, 176 
Boron salts, 255 
Brazil, diamonds in, 278 


British weights and measures, 
basis of, 325, 326 
Brittle silver ore, 159 
Bromic silver, 160 
Bromyrite, 160 
Brookite, 216 
Brown coal, 258 
hematite, 207 
iron ore, 207 

pADMIUM, 238 
\J Cairngorm, 301 
Calamine, 201 
Calcite crystals, 74 
California, auriferous belt of, 137 
gold-bearing beds in, 54 
quicksilver-bearing belt of, 
223, 224 

Gulch, Col., section of strata 
in, 187 

Candle flame, colors of, 59 
Cannel coal, 258 
Carbonate of lead, 185, 186’ 
soda, 57, 58ji 

Carbonates, 2 

mineral, detection of, 88, 89 
Carnelian, 299 
Casing, 39 
Cassiterite, 192-198 

as a type of a strongly marked 
class of deposits, 197 
associations of, 197, 198 
Cat’s eye, 301 
Cement, 128 
Cerargyrite, 158, 159 
Cerussite, 185, 186 
Ceylon graphite, 263 
Chalcedony, 3, 298, 299 
Chalcocite, 172 

Chalcopyrite, 16, 173, 174, 226, 
227 

Charcoal, 59 

Chemical elements, their symbols, 
atomic weights and specific 
gravities, 339, 340 
substances, common names 
of, 341, 342 

tests, changes in minerals by, 
56, 57 
Chert, 260 
Chile saltpetre, 268 



INDEX. 


3G7 


China clay, 256 
Chlorite, 10 
Chromate of lead, 188 
Chrome iron, 208, 209 
Chromite, 208, 209 
Chromium oxide, detection of, 96 
test for, 95 

Chrysocolla, 174, 175 
Chrysoprase, 299 
Cinnabar, 221, 222 
Citrine, 300 
Clays, 255-257 
Cleavage, 16 
Coal, 257-259 
Cobalt, 236-238 

detection of, 88, 97 
wad, 238 
Cobaltite, 237 
Colemanite, 255 

Color of rocks as a guide to the 
prospector, 45, 46 
Colors, accidental, 14 
of minerals, 13-15 
Compass, use of, in searching for 
ore, 214, 215 

Comstock lode, extent of, 165 
sections of, 163 
Conchoidal fracture, 17 
Copper, 170-183 

blue carbonate of, 175, 176 
glance, 172 

green carbonate of, 175 
native, 170, 171 
natural combinations of, 171 
nickel, 225, 226 
ore, assay of, 110 
ores, decomposition of, 41, 42 
more important,171-176 
outcrop of, 41, 42 
pyrites, 16, 173, 174 
variegated, 176 
separation of, 229 
sulphide, detection of, 99 
testing a mineral for, 170,171 
to obtain the per cent, of, in 
an ore, 180-183 
world’s supply of, 176, 177 
Coprolites, 250 
Corundum, 285-290 
properties of, 287 
types of, 286 


Country, 39 
Cradle, 120, 121 
Crocoite, 188 

Crucible, melting ore in a, 107, 
108 

Crucibles, 101 
Cryolite, 241, 242 
Crystallography, 69-76 

systems, illustrations of, 75, 
76 

Cube, 70, 71 
Cullinan diamond, 285 
Cupel, 102 

stains indicative of the pres¬ 
ence of metals, 109 
Cupellation, 106, 107 
Cuprite, 171, 172 

I BARTON’S gold test, 132, 133 
1^ Death Valley, borax of, 254 
255 

Dechenite, 218 
Deposit, indications of a, 37 
Deposits, alluvial, examination 
of, 47-49 
forms of, 49-51 
minerals occur¬ 
ring in, 54 

irregular, 42 
surface, 43, 44 
Descloizite, 218 
Diabase, 5 
Diamond, 277-285 
black, 281 
colors of, 281 
criterion of value of, 282 
drill, 338 

natural surface of, 280, 281 
power of refraction of, 282 
properties of, 281 
rough, 280 

Diamonds, occurrence of, 277-280 
Diaspore, 239 
Dichroiscope, 275, 276 
Diorite, 5 
Dip of lode, 39 
rocks, 36 
Dodecahedron, 71 
Dolerite, 31 

Dolly Hide Mine, Maryland, sec¬ 
tion of copper bed at, 178 



368 


INDEX. 


Dolomite, 259 
Domes, 74 

Dredging for gold, 128 
Dry assay of ores, 101-111 
Ductility, 20 
Dykes, volcanic, 31 

E AGLE vein, Lake Superior, 
section of, 179 

Earth’s crust, movements of, 28 
Earthy cobalt, 238 
fracture, 17 
Elasticity, 19 
Elaterite, 319 

Electricity, prospecting by means 
of, 323-325 

Elements, chemical, calculation 
of the amounts 
of, in a min¬ 
eral, 11 

rule for finding 
the propor¬ 
tional parts by 
weight of the, 
341 

their symbols, 
atomic weights 
and specific 
gravities, 339, 
340 

Emerald, 291, 292 
nickel, 226 
Emery, 287 

Emma Mine, Utah, 168 
English length, 326 
Epidote, 295 
Erubiscite, 176 
Erythrite, 237 

Eureka Mines, Nevada, 167, 168 
Excelsior diamond, 284, 285 
Excess, definition of, 96 
Eye agate, 298 

F ALSE galena, 201, 202 
lead, 201, 202 
topaz, 300 

Faults, displacement due to, 37 
Feldspar, 3-5, 259, 260 
crystals, 75 

Filtrate, examination of, 94, 95 
Fire lute, 111 


Fire opal, 296 

Flame, illustration of character¬ 
istic power of either, 61 
of candle, colors of, 59 
Flexibility, 19 
Flint, 3, 260 
Float galena, 52 
gold, 129 
Florentine, 284 
Fluorite, 260, 261 
Fluorspar, 260, 261 
Flux, 146 

for melting ore in a crucible, 
107 

Foleyrite, 227 
Foliated tellurium, 149 
Foot wall, 39 
Form of minerals, 25, 26 
Formations, 39 
Fracture, 17 
Franklinite, 206 
French measures, 330, 331 
Fuller’s earth, 257 
Fuming nitric acid, 143 
Furnace, assay, 102, 103 
Fusibility, 22 

G alena, 184,185 

limestone, section of, 190 
testing of, for silver, 184 
Garnet, 293, 294 
Garnierite, 236 

Gems and precious stones, 273- 
306 

characteristics of, 304-306 
Gemstones known to occur in the 
United States, 302, 303 
occurring only in the United 
States, 303 

species and varieties of, not 
yet identified in any form 
in the United States, 303 
Geological horizons, 28 
Geology of bismuth, 224 

copper, 177-180 
galena ores, 185 
gold, 135-141 
iron, 210-212 
lead, 189-191 
silver ores, 162-169 
zinc, 202, 203 







INDEX. 


369 


Geology, practical, 28-55 

prospecting, mining, min¬ 
eralogy, etc., glossary of 
terms used in connection 
with, 345-363 
Gibsite, 239 
Glance coal, 258 

Glass bottle, cutting off the bot¬ 
tom of a, 93 

tubes, tests of minerals in, 
67, 68 

Glassy luster, 21 
Glossary of terms used in connec¬ 
tion with prospecting, mining, 
mineralogy, geology, etc., 345- 
363 

Gneiss, 32 
Gold, 112-147 
amalgam, 134 

amalgamating assay for, ISO- 
132 

and silver, specific gravity of 
ores associated with, 331 
assay of, by the touchstone, 
333-335 

-bearing beds in California, 54 
wash, quartz stones in, 
46, 47 

chief producing localities of, 
in the United States, 113 
crystallization of, 114, 115 
detection of, 100 
distribution of, 112, 113 
dredging for, 128 
ductility of, 20 
free, occurrence of, 138 
ground sluicing for, 124, 125 
hydraulic mining of, 125-128 
in alloys, estimation of, 335, 
336 

combination, 141 
iron sulphides, 141 
metallic sulphides, separa¬ 
tion of, 141-146 
rock and drift, 137 
instruments for the discovery 
of, 117, 118 

ironstone blowout as an indi¬ 
cation of, 138 

methods of recovering, in 
Alaska, 123-125 

24 


Gold, native, detection of a con¬ 
tent of, in pyrites, 114 
determination of, 87 
occurrence of, 135 
occurrence of, 113 

in other forms, 
133-135 
quartz, 135 

ores, preparation of, in the 
scorifier, 106 
original position of, 135 
. panning, 118-120 

pilot stones as an indication 
of, 46 

product of Alaska, 113 
profitable mining of, 145 
properties of, 115-117 
quartz, assaying of, 108, 109 
rule for ascertaining the 
amount of, in a lump of 
auriferous quartz, 146,147 
standard value of, in differ¬ 
ent countries, 336 
test, Darton’s, 132, 133 
Tungusian mode of searching 
for, 53 

Grand Duke of Tuscany, 284 
Granite, 34, 35, 139 

metamorphic, composition 
of, 140 

rocks, origin of, 32 
Graphic granite, 34 
tellurium, 150 
Graphite, 261-264 

testing the purity of, 263, 264 
Gray copper ore, 172, 173 
Green carbonate of copper, 175 
jade, 8 

Greenockite, 238 
Greenstone, 31 
Greisen, 198 

Ground sluicing, 124, 125 
Guadalcazarite, 222 
Gurley’s Norwegian compass, 212, 
213 

Gypsum, 264, 265 

H ACKLY fracture, 17 
Hammers, 337 
Hanging wall, 39 
Hardness, 17-19 





370 


INDEX. 


Hardness, scale of, 18 
testing the, 18, 19 
Harlequin opal, 296 
Heavy spar, 253, 254 
Heights, inaccessible, to measure, 
77-79 

Hematite, brown, 207 
red, 206, 207 
Hessite, 149 
Hexagonal prism, 73 
system, 72-74 
Hope diamond, 284 
Horizons, geological, 28 
of rocks, 28 
Hornblende, 7, 8 
Horn silver, 158, 159 
Hornstone, 3, 260 
Horse, 39 

Hydraulicking or hydraulic min¬ 
ing, 125-128 

Hydrogen, apparatus for evolv¬ 
ing, 231-233 

sulphide, apparatus for, 93,94 

1 DRIA, Austria, cinnabar at, 
222, 223 

Igneous rock, 27, 30-32, 139, 140 
Illinois, order of strata in the 
galena district of, 185 
India, diamonds in, 277 
Indicative plants, 52, 53 
Infusorial earth, 266 
Inner flame, 59 
Instruction, preparatory, 1-36 
Intrusive rocks, 31 
Iowa, order of strata in the galena 
district of, 185 
Iridium, 155 
Iron, 203-215 

assay of, 103, 104 
detection of, 96 
geology of, 210-212 
indications of, 52 
meteoric, 203-205 
most important ores of, 205- 
210 

native, 203-205 
pyrites, 16, 209 
sulphides, gold in, 141 
use of magnetic needle in 
prospecting for, 212-215 


Ironstone blow-out, 138 
Irregular deposits, 42 
Isometric system, 69-71 
Itacolumite, 19, 135 

J ACINTH, 72 
Jack’s tin, 227 
Jade, 8 
Jasper, 299 
opal, 296 
Jet, 259 

Johnson, J. C. F., directions for 
an amalgamating assay by, ISO- 
132 

Jubilee diamond, 284, 285 
Jumpers, 337 

K aolin, 256 

Kermesite, 242 

Kirkpatrick, T. S. G., process of 
assaying gold quartz recom¬ 
mended by, 108 
Koh-i-noor, 282 

L ABRADORITE, 5 

Lake George diamonds, 300 
Lake Superior copper region, 
section of strata in, 
179 

iron ores, geologic 
horizons around, 
210 

Lava, 31 
Lazulite, 76 
Lead, 184-191 

and tin, 184-199 
antimony ores, 188, 189 
assay of, 103, 104 
carbonate of, 185, 186 
chief sources of, in the 
United States, 191 
chromate of, 188 
deposit in a fissure of lime¬ 
stone,‘section of, 192 
detection of, 92, 99 
geology of, 189-191 
indication of, 52 
lode in micaceous schist, 186 
mines, circulation of water 
in, 190, 191 
native, 184 






INDEX. 


Lead ochre, 188 
; - ore, assay of, 109, 110 
phosphate of, 187, 188 
sulphate of, 187 

Leadville, Col., carbonate of lead 
at, 186 
Ledge, 39 

Length, English, 326 
French, 330 

particular measures of, 326 
Lepidolite, 7 
Lepidomelane, 6, 7 
Lignite, 258 
Lime, detection of, 87 
Limestone, indication of, 52 

section of lead deposit in a 
fissure of, 192 
Limonite, 207 
Limpid quartz, 3 
Line, inaccessible, to measure an, 
82-84 

Linnseite, 237, 238 
Lithia mica, 7 

Lithographic limestone, 265, 266 
Location, instructions on, 343,344 
Lode, dip of a, 39 

examination of a, 54 
prospecting, 129-132 
strike of a, 39 
walls of a, 39 
Lodes, 38-42 

auriferous, 44, 45 
Long tom, 121-123 
Luster, 21 
Lydian stone, 3 

M agnesia, detection of, 87 
Magnesian mica, 267 
Magnetic iron ore, 205, 206 

needle, use of, in prospecting 
for iron ore, 212-215 
Magnetite, 205, 206 
Malachite, 175 
Malleability, 20 
Manganese, 244-248 
carbonate, 246 

detection of, 97 
detection of, 87 
ores, classes of, 244 
Massicot, 188 
Measure, solid, 327, 331 


Measure, surface, 326, 327 
Measures and weights, 325-331 
Meerschaum, 266 
Mercury, 220-224 

bismuth, nickel, cobalt and 
cadmium, 220-238 
chloride, detection of, 98 
detection of, 88, 92 
native, 220, 221 
ore, assay of, 110 
oxide, detection of, 98 
selenide of, 221 
sulphide of, 221, 222 
Metacinnabarite, 222 
Metallic adamantine luster, 21 
luster, 21 

sulphides, separation of gold 
in, 141-146 

Metalliferous veins, association of 
minerals in, 54, 55 
Metals, cupel stains indicative of 
the presence of, 109 
locality of, 43 
native, colors of, 15, 16 
specific gravity of, 331-333 
Metamorphic rocks, 32, 33, 139 
Meteoric iron, 203-205 
Mexican rliodium-gold, 114 
Mexico, emerald mine in, 292 
Mica schist, 32, 33 
Micas, 5-7, 266, 267 
Microcosmic salt, 57 
Middletown, Conn., lead lode in 
micaceous schist in mine near, 
186 

Milk opal, 296 
Millerite, 226 
Mills, power for, 336, 337 
Mineral, calculation of the 
amounts of the elements in 
a, 11 

carbonates, detection of, 88, 

89 . . 

definition of a, 2 
testing a, for copper, 170,171 
an outcrop of a, 39, 40 
the hardness of a, 18, 19 
Mineralogy, prospecting, mining, 
geology, etc., glossary of 
terms used in connection 
with, 345-363 



372 


INDEX. 


Mineralogy, special, 112-322 
technical, 2-28 

Minerals, argentiferous, 161, 162 
associated with tin, 198 
association of, in metallifer¬ 
ous veins, 54, 55 
change in, by chemical tests, 
56, 57 

chemical tests for, 56, 57 
cleavage of, 16 
colors of, 13-15 
composition of, 11 
decomposition of, 41, 42 
ductility of, 20 
elasticity of, 19 
flexibility of, 19 
form of, 25, 26 
forming principal constitu¬ 
ents of rocks, 2 
fracture of, 16 
fusibility of, 22 
hardness of, 17-19 
luster of, 21 
malleability of, 20 
means of chemically testing, 
before the blow-pipe, 63 
of common occurrence, spe¬ 
cific gravity of, 332, 333 
phosphorescence in, 15 
polychroism in, 14, 15 
properties of, 2 
rocks associated with, 26 
rule for finding the specific 
gravity of, 22, 23 
smell of, 19, 20 
streak of, 17 
taste of, 20 

test of, in glass tubes, 67, 68 
various useful, 249-272 
weight of, 25, 26 
Mining, prospecting, mineralogy, 
geology, etc., glossary of 
terms used in connection 
with, 345-363 
superstitions, 44, 45 
Mispickel, 209, 210 
Molybdenite, 215 
Molybdenum, 215 
Monoclinic system, 75 
Moonstone, 260 
Moss agate, 298 


Mountain cork, 8 
leather, 8 
of light, 282 
wood, 8 

Muscovite, 5, 6, 267 
Mud volcanoes, 312 
Muffle, 102 

N ATIVE amalgams, 221 
Nayagite, 149 
Nephrite, 8 

New Caledonia, nickel in, 236 
Nicolite, 225, 226 
Nickel, 224-236 

and cobalt, analysis of ores 
for, 228-236 
separation of 234— 
236 

arsenide, 225, 226 
detection of, 88, 97 
Nitrate of cobalt, 57 
Nitre, 267, 268 
Nitric acid, fuming, 143 
Nome, Alaska, beach placers of, 
51 


O BSIDIAN, 31 

Occidental topaz, 300 
Octahedrite, 216 
Octahedron, 71 
Ohio oil district, 307, 308 
Oil-bearing sandstone, 311, 312 
sand, contour map of an, 317 
Oligoclase, 4 
Onyx, 301 
Opal, 3, 295,_ 296 
Ore, to obtain the per cent, of 
copper in an, 180-183 
Ores, analysis of, 86-111 

for nickel and 
cobalt, 228-236 
associated with gold and sil¬ 
ver, specific gravity of, 331 
dry assay of, 101-111 
lead antimony, 188, 189 
preliminary examinations of, 
86-89 

qualitative analysis of, 89 
sampling and pulverizing. 
105, 106 






INDEX. 


373 


Ores, specific gravity 0 f, 331-333 
wet method of analysis, 89- 

101 

Oriental amethyst, 285 
emerald, 285 
jade, 8 
topaz, 285 
Orloff, 282, 283 
Orpiment, 252 
Orthoclase, 4, 35, 259, 260 
Orthorhombic system, 74, 75 
Osmium, 155 

Outcrop of copper lodes, 41, 42 
testing a, of a mineral, 39, 40 
Outer flame, 59 
Oxidizing flame, 59 
Ozocerite, 318-320 

P ALLADIUM, 155 

Panning gold, 118-120 
Peacock ore, 174 
Pearly luster, 21 
Peat, 321, 322 

Pelton wheel, rules applicable to, 
336, 337 

Pennsylvania oil regions, facts 
with reference to the, 307 
Petite Anse Island, salt deposit 
in, 269 

Petroleum, bed-like occurrence 
of, 314 

crude, occurrence of, 307 
properties of, 309 
indications of, 309, 310 
occurrence of, in definite 
geological horizons, 313 
outcrops of, 314 
outfit in prospecting for, 309 
ozocerite, asphalt, peat, 307- 
322 

surface, quality of, 318 
vein-like occurrence of, 316 
water-test for, 310, 311 
Petzite, 149, 150 
Phenacite, 292, 293 
Phlogopite, 6 

Phosphate, indication of, 52, 53 
of lead, 187, 188 
lime, 249-251 
Phosphates, white, 251 
Phosphorescence, 15 


Pilot Knob, Missouri, section of, 
211 

stones, 46 
Pitch-blende, 217 
Pitt, 284 

Placer diggings, character of, 49- 

51 

gold, 47, 134 
Placers, 47 

Plagioclastic feldspars, 4 
Plants, indicative, 52, 53 
Plaster of Paris, 265 
Plastic clay, 256 
Platinum, 150-155 

chemical test of, 153, 154 
detection of, 100 
occurrence of, 151, 152 
properties of, 152, 153 
value of, 152 
wire loop, 61 
Plumbago, 261-264 
Plutonic rocks, 30 
Polychroism, 14, 15 
Porcelain clay, 256 
Porphyritic granite, 34 
Potash alum, 249 
feldspar, 35 
mica, 267 
Pottery clay, 256 
Power for mills, 336, 337 
Precious stones and gems, 273-306 
Preparatory instruction, 1-36 
Prism compass, 84 
Prospecting by means of elec¬ 
tricity, 323-325 
lodes, 129-132 
mining, mineralogy, geology, 
etc., glossary of terms used 
in connection with, 345- 
363 

starting point for, 43 
Prospector, color of rocks as a 
guide to the, 45, 46 
Prospectors’ pointers, 343, 344 
Proustite, 159, 160 
Psilomelane, 245, 246 
Pulverizing ores, 105, 106 
Pyrargvrite, 159, 160 
Pyrite, 16 

Pyrites, detection of a content of 
native gold in, 114 





374 


INDEX. 


Pyrites, estimating the sulphur 
in, 271, 272 
Pyrolusite, 245 
Pyromorphite, 187, 188 
Pyropissite, 319 
Pyroxene, 8-10 
Pyrrhotite, 226 

UALITATIVE analysis of 
ores, 89 
Quartz, 3 

auriferous, rule for ascertain¬ 
ing the amount of gold in 
a lump of, 146, 147 
cellular, 136 
crystals, 73 

judging the character of, 136 
measuring up of, 41 
occurrence of gold in, 135 
rocks, 130 

Quicksilver, 220-224 

R ealgar, 252 

Red copper ore, 171, 172 
hematite, 206, 207 
oxide of zinc, 201 
Reducing flame, 59 
Reef, 39 
Regent, 284 
Resin opal, 290 
Resinous luster, 21 
Retinite, 319 

Retort, construction of a, 131 
Rhodium gold, Mexican, 114 
Rhodocrosite, 246 
Rhombic prism, 74 
pyramid, 74 

Right-hand theory, 44, 45 
River and creeks/ wash of, 46, 47 
right- and left-hand branches 
of a, 44 
Roasting, 61 
Rock, azoic, 27 

crystal, 299, 300 
definition of a, 29 
igneous, 27 
salt, 208-270 
Rocker, 120, 121 
Rocks, aqueous, 33 

associated with minerals, 26 
changes in, 35, 36 


Rocks, classification of, 29 

color of, as a guide to the 
prospector, 45, 46 
dip of, 36 
• geologic, 26 

granite, origin of, 32 
horizons of, 28 
igneous, 30-32, 139, 140 
intrusive, 31 

metamorphic, 32, 33, 139 
plutonic, 30 

principal constituents, 2 
specific gravity of, 331-333 
strike of, 36 

table showing the relations of 
certain, one to another, 30- 
33 

volcanic, 30 
Rose quartz, 300 
Ruby, 288-290 

copper, 171, 172 
silver, 159, 160 
Rutile, 215, 216 

S ALSES, 312 

Salt deposits, 268-270 
Saltpetre, 267, 268 
Salts, 12 

Sampling ores, 105, 106 
Sandstone, 33 

oil-bearing, 311, 312 
Sandstones, examination of, 89 
Sapphire, 285, 287, 288 
Sard, 299 
Sardonyx, 301 
Satin spar, 265 
Scales, 104 
Scorifiers, 101 
Selenide of mercury, 221 
Selenite, 265 

Selenium, detection of, 86 
Sepiolite, 266 
Serpentine, 11 
Shaft, sinking a, 40, 41 
Shale, 34 
Siderite, 207, 208 
Silicate of copper, 174, 175 
Silicates, 12 
Silky luster, 21 
Silver, 155-169 

chemical test of, 156 




INDEX. 


375 


Silver, glance, 157, 158 
indication of, 53, 86 
native, 155, 156 

determination of, 87 
ores, geology of, 162-169 
preparation of, in the 
scorifier, 106 
valuing of, 160, 161 
source of, 157 

sulphide with antimony, 159 
sulphides, 157 

test for the presence of, in 
argentiferous minerals, 
161, 162 

testing galena for, 184 
Slate, 270 
Sluices, 125 

Small conchoidal fracture, 17 
Smaltite, 225, 236, 237 
Smell, 19, 20 
Smithsonite, 2Q0 
Smoky quartz, 301 
Soapstone, 272 
Soda alum, 249 
Solid measure, 327, 331 
Spanish topaz, 300 
Sparta, New Jersey, zinc mines, 
section of strata near, 202, 203 
Spathic iron ore, 207, 208 
Specific gravity, 22-25 

of metals, ores, rocks, 
etc., 331-333 
rule for finding the, 
22, 23 

weight by, 327-329 
Specular ore, 206, 207 
Sperrylite, 152, 154 
Sphalerite, 201, 202 
Splintery fracture, 17 
Stannous chloride, preparation 
of, 154 

Star of South Africa, 284 
Steatite, 272 
Stephanite, 159 
Stibnite, 242, 243, 244 
Stone coal, 258 
Streak, 17 
Stream tin, 193 
Strike of a lode, 39 
rocks, 36 

Sub-conchoidal fracture, 17 


Sudbury, Canada, sources of 
nickel in, 226 
Sulphate of lead, 187 
Sulphates, 2 

Sulphide of mercury, 221, 222 
tin, 194 
zinc, 201, 202 

Sulphides, metallic, separation of 
gold in, 141-146 
Sulphur, 270-272 

detection of, 86, 99 
Sunstone, 260 
Surface deposits, 43, 44 
measure, 326, 327 
French, 330 
Surveying, 77-85 
Swampy puddles, examination of, 
for oil, 312 
Sylvanite, 150 

Systems of crystallography, 69 

T ABLE showing association of 
minerals in metal¬ 
liferous veins, 54, 
55 

the relations of cer¬ 
tain rocks, one to 
another, 30-33 
Talc, 10, 11, 272 
Taste, 20 

Technical mineralogy, 2-28 
Tellurides, 148-150 
Tellurium, 148 

platinum, silver, 148-169 
Test acid, 334 
Tests in glass tubes, 67, 68 
Tetragonal octahedron, 72 
prism, 72 
system, 71, 72 
Tetrahedrite, 172, 173 
Texas, Gulf Coastal Plain oil field 
of, 308 

tin in, 195, 196 
Tin, 191-199 

detection of, 87 
granites, 198 

minerals associated with, 198 
occurrence of, in the United 
States, 195, 196 
ore, assay of, 110, 192 
pjrite, 194 






376 


INDEX. 


Tin stone, 192-198 
sulphide of, 194 
Titanium, 215, 216 
detection of, 88 
Toad-eye tin, 193 
Tonopah district, geology of, 165, 
167 

Topaz, 290, 291 
Touchstone, 3 

assay of gold by the, 333-335 
Tourmaline, 294, 295 
Trachyte, 31 
Traps, 31 
Tremolite, 7 
Troy weight, 327 
Tungstate of soda, 199 
Turquois, 76, 297 

U NDERLIE, 39 

United States, asphalt in the, 
321 

borax in, 254, 255 
chief gold pro¬ 
ducing local- 
ties in, 113 
sources of lead 
in, 191 

corundum locali¬ 
ties in, 285, 286 
diamonds in, 279, 
280 

emerald in, 292 
gem-stonesknown 
to occur in 
the, 302, 
303 

occurring 
only in 
the, 303 

graphite in, 262, 
263 

manganese mines 
in, 246, 247 
occurrence of tin 
in, 195, 196 
petroleum in, 
307-309 

platinum in the, 
151. 

rubies in, 289 
salt deposits in, 
268-270 


United States, sapphires in, 288 
species and varieties of 
gem-stones not yet 
identified in any form 
in the, 303 
topaz in, 291 
turquois in, 297 
weights and measures, 
basis of, 325, 326 
Uraninite, 217 
Uranium, 216, 217 
detection of, 88 

Y ANADINITE, 218 
Vanadium, 218, 219 
detection of, 88 

Variegated copper pyrites, 176 
Veins, metalliferous, association 
of minerals in, 54, 55 
Victoria, 284 
Vitreous copper ore, 172 
luster, 21 
Volborthite, 218 
Volcanic dykes, 31 
rocks, 30 


W ALLS of a lode, 39 

Wash of rivers and creeks, 
46, 47 

Water-test for petroleum, 310, 
311 


Wax opal, 296 
Waxy luster, 21 
Weight, avoirdupois, 327 

by specific gravity, 327-329 
French, 331 
of minerals, 25, 26 
Troy, 327 
Weights, 104 

and measures, 325-331 
special, 329, 330 
Whartonite, 227 
White jade, 8 

lead ore, 185, 186 
mica, 267 
phosphates, 251 
Willemite, 201 

Wisconsin, order of strata in the 
galena district of, 185 
Witherite, *253,1,254 
Wolframite, 199 



INDEX. 


377 


Wood jasper, 299 
opal, 296 
tin, 193 


Y ellow flame, 59 

quartz, 300 

Z INC, 200-203 

blende, 201, 202 
blow-pipe test for, 203 


Zinc carbonate, 200 
detection of, 87 
geology of, 202, 203 
indication of, 53 
iron, molybdenum, titan¬ 
ium, uranium, vanad¬ 
ium, 200-219 
red oxide of, 201 
sulphide of, 201, 202 
Zincite, 201 
Zircon, 72, 293 













































































































































* 




I • 















































































































% 






















o^-T^nLoa-TJE 

OF 

practical and Scientific Booths 

PUBLISHED BY 

Henry Carey Baird & Co. 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS. 

810 Walnut Street, Philadelphia. 


*®~Any of the Books comprised in this Catalogue will he sent by ma: J ( f ree 0 f 
postage, to any address in the world, at the publication prices. 

A Descriptive Catalogue, 90 pages, 8vo., will he sent free and free of postage, 
to any one in any part of the world, who will furnish his address. 

fST- Where not otherwise stated, all of the Books in this Catalogue are bousf 

in muslin. 


AMATEUR MECHANICS’ WORKSHOP: 

A treatise containing plain and concise directions for the manipula¬ 
tion of Wood and Metals, including Casting, Forging, Brazing, 
Soldering and Carpentry. By the author of the “ Lathe and Itf 
Uses.” Seventh edition. Illustrated. 8vo. . . . $2-5i 

ANDES.—Animal Fats and Oils: 

Their Practical Production, Purification and Uses; their Properties^ 
Falsification and Examination. 62 illustrations. 8vo. . $4.00 

ANDES.—-Vegetable Fats and Oils: 

Their Practical Preparation, Purification and Employment; theif 
Properties, Adulteration and Examination. 94 illustrations. 8vo. 

$4.00 

ARLOT.—A Complete Guide for Coach Painters: 

Translated from the French o r M. Arlot, Coach Pain* er, for 
eleven years Foreman of Pairing to M. Eherler, Coach Maker, 
Paris. By A. A. Fesquet, Chemist and Engineer. To hich is 
added an Appendix, containing Informa**™ 1 »e*oecting the P aterials 
and the Practice of Coach and Car Painting Varnishinj. in the 
United States and Great Britain 121*10. • • . $1.25 


(*) 





HENRY CAREY BAIRD & CO.’S CATALOGUE. 




4.RMENGAUD, AMOROUX, AND JOHNSON.—The Practi- 
,al Draughtsman’s Book of Industrial Design, and Ma¬ 
chinist’s and Engineer’s Drawing Companion : 

Farming a Complete Course of Mechanical Engineering and Archi¬ 
tectural Drawing. From the French of M Armengaud the elder, 
t'rof. of Design in the Conservatoire of Arts and Industry, Paris, and 
M Armengaud the younger, and Amoroux, Civil Engineers. Re¬ 
writ :n and arranged with additional matter and plates, selections from 
and xamples of the most useful and generally employed mechanism 
of t ; day. By William Johnson, Assoc. Inst. C. E. Illustrated 
by fi y folio steel plates, and fifty wood-cuts. A new edition, 4to., 
cloth . ......... $ 6.00 

ARM ,TRONG.—The Construction and Management of Steam 
rjoilers : 

By R. Armstrong, C. E. With an Appendix by Robert Mallet, 
C. E., F. R. S. Seventh Edition. Illustrated, i vol. i2mo. .60 

ARROWSMITH.—The Paper-Hanger’s Companion: 

Comprising Tools, Pastes, Preparatory Work ; Selection and Hanging 
of Wall-Papers ; Distemper Painting and Cornice-Tinting ; Stencil 
Work; Replacing Sash-Cord and Broken Window Panes ; and 
Useful Wrinkles and Receipts, By James Arrowsmith. A New, 
Thoroughly Revised, and Much Enlarged Edition. Illustrated by 
25 engravings, 162 pages. (1905) .... $1.00 

ASHTON.—The Theory and Practice of the Art of Designing 
Fancy Cotton and Woollen Cloths from Sample : 

Giving full instructions for reducing drafts, as well as the methods of 
spooling and making out harness for cross drafts and finding any re¬ 
quired reed; with calculations and tables of yarn. By Frederic T. 
Ashton, Designer, West Pittsfield, Mass. With fifty-two illustrations. 
One vol. folio ........ $5.00 

ASKINSON—Perfumes and their Preparation: 

A Comprehensive Treatise on Perfumery, containing Complete 
Directions for Making Handkerchief Perfumes, Smelling-Salts. 
Sachets, Fumigating Pastils; Preparations for the Care of the Skin, 
the Mouth, the Hair; Cosmetics, Hair Dyes, and other Toilet 
Articles. By G. W. Askinson. Translated from the German by IsiDOR 
Furst. Revised by Charles Rice. 32 Illustrations. Svo. $3.00 

0RONGNI ART.—Coloring and Decoration of Ceramic Ware. 
8 vc .$2.50 

BAIRD.—The American Cotton Spinner, anc Manager’s and 
Carder’s Guide: 

A Practical Treatise on Cotton Spinning; giving the Dimensions and 
Speed of Machinery, Draught and Twist Calculations, etc.; with 
notices of recent Improvements: together with Rules and Examples 
ror making changes in the sizes and numbers of Roving and Yarn. 
Compiled from the papers the late Robert H. Baird. i2mo. 

$1.50 









HENRY CAREY BAIRD & CO.’S CATALOGUE. 


3 


BAKER.—Long-Span Railway Bridges : 

Comprising Investigations of the Comparative Theoretical and 
Practical Advantages of the various Adopted or Proposed Type 
Systems of Construction ; with numerous Formulae and Tables. By 
B. Baker. i2mo. $1.00 

BRAN NT.—A Practical Treatise on Distillation and Rec¬ 
tification of Alcohol: 

Comprising Raw Materials ; Production of Malt, Preparation of 
Mashes and of Yeast; Fermentation ; Distillation and Rectification 
and Purification of Alcohol ; Preparation of Alcoholic Liquors, 
Liqueurs, Cordials, Bitters, Fruit Essences, Vinegar, etc.; Examina¬ 
tion of Materials for the Preparation of Malt as well as of the Malt 
itself; Examination of Mashes before and after Fermentation ; Alco- 
holometry, with Numerous Comprehensive Tables ; and an Appendix 
on the Manufacture of Compressed Yeast and the Examination of 
Alcohol and Alcoholic Liquors for Fusel Oil and other Impurities. 
By William T. Brannt, Editor of “ The Techno-Chemical Receipt 
Book.” Second Edition. Entirely Rewritten. Illustrated by 105 
engravings. 460 pages, 8vo. (Dec., 1903) . . . $4.00 

BARR.—A Practical Treatise on the Combustion of Coal: 
Including descriptions of various mechanical devices for the Eco¬ 
nomic Generation of Heat by the Combustion of Fuel, whether solid, 
liquid or gaseous 8vo. ....... $2.50 

BARR.—A Practical Treatise on High Pressure Steam Boilers: 
Including Results of Recent Experimental Tests of Boiler Materials, 
together with a description of Approved Safety Apparatus, Steam 
Pumps, Injectors and Economizers in actual use. By Wm. M. Barr. 
204 Illustrations. 8vo. ....... $3.00 

BAUERMAN.—A Treatise on the Metallurgy of Iron : 

Containing Outlines of the History of Iron Manufacture, Methods of 
Assay, and Analysis of Iron Ores, Processes of Manufacture of Iron 
and Steel, etc., etc. By H. Bauerman, F. G. S., Associate of the 
Royal School of Mines. Fifth Edition, Revised and Enlarged. 
Illustrated with numerous Wood Engravings from Drawings by J. B. 

Jordan. i 2 mo,. $2.00 

BRANNT.—The Metallic Alloys : A Practical Guide 

For the Manufacture of all kinds of Alloys, Amalgams, and Solders, 
used by Metal-Workers : together with their Chemical and Physical 
Properties and their Application in the Arts and the Industries ; with 
an Appendix on the Coloring of Alloys and the Recovery of Waste 
Metals. By William T. Brannt. 45 Engravings. Third, Re¬ 
vised, and Enlarged Edition. 570 pages. Svo. . Net, $5.00 
BRANNT.—The Soap Maker’s Hand-Book of Materials, Processes 
and Receipts for Every Description of Soap. Illustrated. 8vo. (In 
preparation.) 

BEANS.—A Treatise on Railway Curves and Location of 
Railroads : 

By E. W. Beans, C. E. Illustrated. i2mo. Tucks. . $1.50 





4 


HENRY CAREY BAIRD & CO.’S CATALOGUE. 


BELL.—Carpentry Made Easy: 

Or, The Science and Art of Framing on a New and Improve* 
System. With Specific Instructions for Building Balloon Frames, Barn 
Frames, Mid Frames, Warehouses, Church Spires, etc. Comprising 
also a System of Bridge Building, with Bills, Estimates of Cost, and 
valuable Tables. Illustrated i>y forty-four plates, comprising nearly 
200 figures. By William E. Bell, Architect and Practical Builder. 
8vo. .... ..... #5.oc 

BEMROSE.—Fret-Cutting and Perforated Carving: 

With fifty-three practical illustrations. By W. Bemrose, Jr. I voL 
quarto .......... $2.50 

BEMROSE.—Manual of Buhl-work and Marquetry: 

With Practical Instructions for Learners, and ninety colored designs, 
By W. Bemrose, Jr. i vol. quarto .... $3.00 

BEMROSE.—Manual of Wood Carving: 

With Practical Illustrations for Learners of the Art, °.nd Original and 
Selected Designs. By William Bemrose, Jr. With an Intro 
duction by Llewellyn Jewitt, F. S. A., etc. With 128 illustra¬ 
tions, 4to.. 52.5a 

BERSCH.—Cellulose, Cellulose Products, and Rubber Sub¬ 
stitutes : 

Comprising the Preparation of Cellulose, Parchment-Cellulose, 
Methods of Obtaining Sugar, Alcohol and Oxalic Acid from Wood- 
Cellulose ; Production of Nitro-Cellulose and Cellulose Esters; 
Manufacture of Artificial Silk, Viscose, Celluloid, Rubber Substi¬ 
tutes, Oil-Rubber, and Faktis. By Dr. Joseph Bersch. Trans¬ 
lated by William T. Brannt. 41 illustrations. (1904.) $ 3.00 

BILLINGS.—Tobacco: 

Its History, Variety, Culture, Manufacture, Commerce, and Various 
Modes of Use. By E. R. Billings. Illustrated by nearly 200 
engravings. 8vo. . . . . . . $3.00 

BIRD.—The American Practical Dyers’ Companion: 

Comprising a Description of the Principal Dye-Stuffs and Chemicals 
used in Dyeing, their Natures and Uses ; Mordants and How Made ; 
with the best American, English, French and German processes for 
Bleaching and Dyeing Silk, Wool, Cotton, Linen, Flannel, Felt, 
Press Goods, Mixed and Hosiery Yarns, Feathers, Grass, Felt. Fur, 
Woo!, and Straw Hats, Jute Yarn, Vegetable Tvorv, Mats, Skins, 
P'urs, Leather, etc., etc. By Wood Aniline, and other Processes, 
together with Remarks on Finishing Agents, and instructions in the 
Finishing of Fabrics, Substitutes for Indigo, Water-Proofing of 
Materials, Tests anl Purification of Water, Manufacture of Aniline 
and other New Dve Wares, Harmonizing Colors, etc., etc. ; embrac¬ 
ing in all over 800 Receipts for C dors and Shades, accompanied by 
170 Dyed Samples of Raw Materials and Fabrics . By F. J. Bird, 
Practical Dyer, Author of “The Dyers’ Hand-Book.” 8 vo. 55.00 





HENRY CAREY BAIRD & CO.’S CATALOGUE 


5 


BLINN.—A Practical Workshop Companion for Tin, Sheet- 
Iron, and Copper-plate Workers; 

Containing Rules Tor describing various kinds of Patterns used by 
Tin, Sheet-Iron and Copper-plate Workers; Practical Geometry; 
Mensuration of Surfaces and Solids; Tables of the Weights of 
Metals, Lead-pipe, etc.; Tables of Areas and Circumference* 
of Circles; Japan, Varnishes, Lackers, Cements, Compositions, etc., 
etc. By Leroy J. Blinn, Master Mechanic. With One Hundred 
and Seventy Illustrations. i2tno. . , . • . $2.50 

BOOTH.—Marble Worker’s Manual: 

Containing Practical Information respecting Marbles in general, theit 
Cutting, Working and Polishing; Veneering of Marble; Mosaics; 
Composition and Use of Artificial Marble, Stuccos, Cements, Receipts, 
Secrets, etc., etc. Translated from the French by M. L. Booth. 
With an Appendix concerning American Marbles. i2mo., cloth $1.50 

BRANNT.—A Practical Treatise on Animal and Vegetable 

Fats and Oils : 

Comprising both Fixed and Volatile Oils, their Physical and Chem¬ 
ical Properties and Uses, the Manner of Extracting and Refining 
them, and Practical Rules for Testing them; as well as the Manufac¬ 
ture of Artificial Butter and Lubricants, etc., with lists of American 
Patents relating to the Extraction, Rendering, Refining, Decomposing, 
and Bleaching of Fats and Oils. By William T. Brannt, Editor 
of the “ Techno-Chemical Receipt Book.” Second Edition, Revised 
and in a great part Rewritten. Illustrated by 302 Engravings. In 

Two Volumes. 1304 pp. 8vo. $10.00 

BRANNT.—A Practical Treatise on the Manufacture of Soap 
and Candles : 

Based upon the most Recent Experiences in the Practice and Science; 
comprising the Chemistry, Raw Materials, Machinery, and Utensils 
and Various Processes of Manufacture, including a great variety of 
formulas. Edited chiefly from the German of Dr. C. Deite, A. 
Engelhardt, Dr. C. Schaedler and others; with additions and lists 
of American Patents relating to these subjects. By Wm. T. Brannt. 
Illustrated by 163 engravings. 677 pages. Svo. . . $12.50 

BRANNT—India Rubber, Gutta-Percha and Balata : 

Occurrence, Geographical Distribution, and Cultivation, Obtaining 
and Preparing the Raw Materials, Modes of Working and Utilizing 
them, Including Washing, Maceration, Mixing, Vulcanizing,Rubber 
and Gutta-Percha Compounds, Utilization of Waste, etc. By Will¬ 
iam T. Brannt. Illustrated. i2mo. (1900.) . . $3.00 




6 HENRY CAREY BAIRD & CO.’S CATALOGUE. 


BRANNT—WAHL.—The Techno-Chemical Receipt Book : 

Containing several thousand Receipts covering the latest, most im¬ 
portant, and most useful discoveries in Chemical Technology, and 
their Practical Application in the Arts and the Industries. Edited 
chiefly from the German of Drs. Winckler, Eisner, Heintze, Mier- 
zinski, Jacobsen, Roller and Heinzerling, with additions by Wm. T. 
Brannt and Wm. H. Wahl, Ph. D. Illustrated by 78 engravings. 
i2mo. 495 pages. ....... $2.00 

BROWN.—Five Hundred and Seven Mechanical Movements : 
Embracing all those which are most important in Dynamics, Hy¬ 
draulics, Hydrostatics, Pneumatics, Steam Engines, Mill and other 
Gearing, Presses, Horology, and Miscellaneous Machinery ; and in¬ 
cluding many movements never before published, and several of 
which have only recently come into use. By Henry T. Brown. 

i2mo.$1.00 

BUCKMASTER.—The Elements of Mechanical Physics: 

By J. C. Buckmaster. Illustrated with numerous engravings. 
i2mo. .......... $1.00 

9ULLOCK.—The American Cottage Builder : 

A Series of Designs, Plans and Specifications, from $200 to $20,000, 
for Homes for the People; together with Warming, Ventilation, 
Drainage, Painting and Landscape Gardening. By John Bullock, 
Architect and Editor of “ The Rudiments of Architecture and 
Building,” etc., etc. Illustrated by 75 engravings. 8vo. 
BULLOCK.—The Rudiments of Architecture and Building: 

For the use of Architects, Builders, Draughtsmen, Machinists, En¬ 
gineers and Mechanics. Edited by John Bullock, author of “ The 
American Cottage Builder.” Illustrated by 250 Engravings. 8vo. $2.50 
SURGH.—Practical Rules for the Proportions of Modern 
Engines and Boilers for Land and Marine Purposes. 

By N. P. Burgh, Engineer. i2mo. ... $1.50. 

BYLES—Sophisms of Free Trade and Popular Political 
Econ.my Examined. 

By a Barrister (Sir John Barnard Byles, Judge of Common. 
Pleas). From the Ninth English Edition, as published by the 
Manchester Reciprocity Association. i2mo. . . . $1.25 

BOWMAN.—The Structure of the Wool Fibre in its Relation 
to the Use of Wool for Technical Purposes: 

Being the substance, with additions, of Five Lectures, delivered at. 
the request of the Council, to the members of the Bradford Technical 
College, and the Society of Dyers and Colorists. By F. H. Bow¬ 
man, D. Sc., F. R. S. E., F. L. S. Illustrated by 32 engravings. 
8vo. . . . ....... 

BY RNE.—Hand-Book for the Artisan, Mechanic, and Engi¬ 
neer : 

Comprising the Grinding and Sharpening of Cutting Tools, Abrasive 
Processes, Lapidary Work, Gem and Glass Engraving, Varnishing 
and Lackering, Apparatus, Materials and Processes for Grinding and 





HENRY CAREY BAIRD & CO.’S CATALOGUE. 


7 


Polishing, etc. By Oliver Byrne. Illustrated by 185 wtiod en¬ 
gravings. 8 vo. ........ $5 00 

3YRNE.—Pocket-Book for Railroad and Civil Engineers: 

Containing New, Exact and Concise Methods for Laying out Railroad 
Curves, Switches, Frog Angles and Crossings; the Staking out of 
work; Levelling; the Calculation of Cuttings: Embankments; Earth* 
work, etc By Oliver Byrne. i8mo., full bound, pocket-book 

form.$1.50 

LYRNE.—Tne Practical Metal-Worker’s Assistant: 

Comprising Metallurgic Chemistry; the Arts of Working all Metal* 
and Alloys; Forging of Iron and Steel; Hardening and Tempering; 
Melting and Mixing; Casting and Founding; Works in Sheet Metals 
the Processes Dependent on the Ductility of the Metals; Soldering; 
and the most Improved Processes and Tools employed by Metal- 
Workers. With the Application of the Art of Electro-Metallurgy to 
Manufacturing Processes; collected from Original Sources, and from 
the works of Holtzapffel, Bergeron, Leupold, Piumier, Napier, 
Scoffern, Clay, Fairbairn and others. By Oliver Byrne. A new, 
revised and improved edition, to which is added an Appendix, con¬ 
taining The Manufacture of Russian Sheet-Iron. By JOHN PERCY, 
M. D., F. R. S. The Manufacture of Malleable Iron Castings, and 
Improvements in Bessemer Steel. By A. A. Fesquet, Chemist and 
Engineer. With over Six Hundred Engravings, Illustrating every 

Branch of the Subject. 8vo.$5.00 

BYRNE.—The Practical Model Calculator: 

For the Engineer, Mechanic, Manufacturer of Engine Work, Naval 
Architect, Miner and Millwright. By Oliver Byrne. 8vo.. nearlv 
600 pages ........ (f carce.) 

CABINET MAKER’S ALBUM OF FURNITUREs 

Comprising a Collection of Designs for various Styles of F rniture. 
Illustrated by Forty-eight Large and Beautifully Engraved Plates. 
Oblong, 8vo. ........ - J 

CALLINGHAM.—Sign Writing and Glass Embossing: 

A Complete Practical Illustrated Manual of the Art. By James 
Callingham. To which are added Numerous Alphabets and the 
Art of Letter Painting Made Easy. By James C. Badenoch. 258 

pages. i2mo..$1.50 

"AMPIN.—A Practical Treatise on Mechanical Engineering: 
Comprising Metallurgy, Moulding, Casting, Forging, Tools, Work, 
shop Machinery, Mechanical Manipulation, Manufacture of Steam- 
Engines, etc. With an Appendix on the Analysis of Iron and Iron 
Ores. By Ffancis Campin, C. E. To which are added, Observations 
on the Construction of Steam Boilers, and Remarks upon Furnaces 
used for Smoke Prevention; with a Chapter on Explosions. Bv R« 
Armstrong, C. E., and John Bourne, (scarce ) 





8 


HENRY CAREY BAIRD & CG.*S CATALOGUE. 


CAREY.—A Memoir of Henry C. Carey. 

By Dr. Wm. Elder, With a portrait. 8vo., cloth . . 75 

CAREY.—The Works of Henry C. Carey: 

Harmony of Interests : Agricultural, Manufacturing and Commer 
cial. 8vo. ..... . $*.25 

Manual of Social Science. Condensed from Carey’s “ Principles 
of Social Science.” By Kate McKean, i vol. i2mo. . $2.00 

Miscellaneous Works. With a Portrait. 2 vols. 8vo. $1000 

Past, Present and Future. 8vo.$2.50 

Prin ,'iples of Social Science. 3 volumes, 8vo. . . $ 10.00 

The Slave-Trade, Domestic and Foreign; Why it Exists, and 
How it may be Extinguished (1853). 8vo. . . . $2.00 

The Unity of Law: As Exhibited in the Relations of Physical, 
Socia 1 , Mental and Moral Science (1872). 8vo. . . $2.50 

CLAR K.—Tramways, their Construction and Working: 

Embracing a Comprehensive History of the System. With an ex¬ 
haustive analysis of the various modes of traction, including horse¬ 
power, steam, heated water and compressed air; a description of the 
varieties of Rolling stock, and ample details of cost and working ex- 
penses. By D. Kinnear Clark. Illustrated by over 200 wood 
engravings, and thirteen folding plates. I vol. 8vo. . $5.0o 

COLBURN.—The Locomotive Engine : 

Including a Description of its Structure, Rules for Estimating its 
Capabilities, and Practical Observations on its Construction and Man¬ 
agement. By Zerah Colburn. Illustrated. i2tno. . $1.00 

POLLENS.—The Eden of Labor; or, the Christian Utopia. 

By T. Wharton Collens, author of “ Humanics,” “The Histoi} 
of Charity,” etc. l2mo. Paper cover, $1.00; Cloth . $1.25 

COOLEY.—A Complete Practical Treatise on Perfumery: 

Being a Hand-book of Perfumes, Cosmetics and other Toilet Article! 
With a Comprehensive Collection of Formulae. By Arnold '. 

Cooley. 121110.$1.5*0 

COOPER.—A Treatise on the use of Belting for the Trans¬ 
mission of Power. 


With numerous illustrations of approved and actual methods of ar¬ 
ranging Main Driving and Quarter Twist Belts, and of Belt Fasten 
ings. Examples and Rules in great number for exhibiting and cal¬ 
culating the size and driving power of Belts. Plain, Particular and 
Practical Directions for the Treatment, Care and Manigement o r 
Belts. Descriptions of many varieties of Beltings, together with 
chapters on the Transmission of Power by’Ropes; by Iron and 
Wood Frictional Gearing; on the Strength of Belting Leather; and 
on the Experimental Investigations of Morin, Briggs, and others. By 

John H. Cooper, M. E. 8vo .$ 3.50 

CRAIK.—The Practical American Millwright and M^ler. 

By David Craik, Millwright. Illustrated by numerous wood en¬ 
gravings and two folding plates. 8 vo. (Scarce.) 





HENRY CAREY BAIRD & CO.’S CATALOGUE. 


9 


CROSS.—The Cotton Yarn Spinner: 

Showing how the Preparation should be arranged for Different 
Counts of Yarns by a System more uniform than has hitherto been 
practiced; by having a Standard Schedule from which we make all 
our Changes. By Richard Cross. 122 pp. i2mo. . 75 

CRISTIANI.—A Technical Treatise on Soap and Candles: 

With a Glance at the Industry of Fats and Oils. By R. S. Cris- 
TIANI, Chemist. Author of “ Perfumery and Kindred Arts.” Illus¬ 
trated by 176 engravings. 581 pages, 8vo. $15.00 

COURTNEY.—The Boiler Maker’s Assistant in Drawing, 
Templating, and Calculating Boiler Work and Tank 
Work, etc. 

Revised by D. K. Clark. 102 ills. Fifth edition. . . 80 

COURTNEY.—The Boiler Maker’s Ready Reckoner: 

With Examples of Practical Geometry and Templating. Revised by 
D. K. Clark, C. E. 37 illustrations. Fifth edition. • $1.60 

DAVIDSON.—A Practical Manual of House Painting, Grain¬ 
ing, Marbling, and Sign-Writing: 

Containing full information on the processes of House Painting in 
Oil and Distemper, the Formation of Letters and Practice of Sign- 
Writing, the Principles of Decorative Art, a Course of Elementary 
Drawing for House Painters, Writers, etc., and a Collection of Useful 
Receipts. With nine colored illustrations of Woods and Marbles, 
and numerous wood engravings. By Ellis A. Davidson. i2mo. 

$2.00 

DAVIES.—A Treatise on Earthy and Other Minerals and 
Mining: 

By D. C. Davies, F. G. S., Mining Engineer, etc. Illustrated by 
76 Engravings. i2mo. ....... $5 00 

DAVIES.—A Treatise on Metalliferous Minerals and Mining: 
By D. C. Davies, F. G. S , Mining Engineer, Examiner of Mines, 
Quarries and Collieries. Illustrated by 148 engravings of Geological 
Formations, Mining Operations and Machinery, drawn from the 
practice of all parts of the world. Fifth Edition, thoroughly Revised 
and much Enlarged by his son, E. Henry Davies. i2mo, 524 

pages. . $5°° 

DIETERICHS.—A Treatise on Friction, Lubrication, Oils 
and Fats: 

The Manufacture of Lubricating Oils, Paint Oils, and of Grease, and 
the Testing of Oils. By E. F. Dieterichs, Member of the Franklin 
Institute; Member National Association of Stationary Engineers; 
Inventor of Dieterichs’Val ve-Oleum Lubricating Oils. iamo. (1906.) 

A practical book by a practical man . 3 1.25 

DAVIS.—A Practical Treatise on the Manufacture of Brick, 
Tiles and Terra-Cotta : 

Including Stiff Clay, Dry Clay, Hand Made, Pressed or Front, and 
Roadway Paving Brick, Enamelled Brick, with Glazes and Colors, 
Fire Brick and Blocks, Silica Brick, Carbon Brick, Glass Pots, Rs- 





JO HENRY CAREY BAIRD & CO.’S CATALOGS. 


torts, Architectural Terra-Cotta, Sewer Pipe, Drain Tile, Glazed and 
Unglazed Roofing Tile, Art Tile, Mosaics, and Imitation of Intarsia, 
or Inlaid Surfaces. Comprising every product of Clay employed in 
Architecture, Engineering, and the Blast Furnace. With a Detailed 
Description of the Different Clays employed, the Most Modern 
Machinery, Tools, and Kilns used, and the Processes for Handling, 
Disintegrating, Tempering, and Moulding the Clay into Shape, Dry¬ 
ing, Setting, and Burning. By Charles Thomas Davis. Third Edi¬ 
tion. Revised and in great part rewritten. Illustrated by 261 
engravings. 662 pages ....... $ 20.00 

DAVIS.—A Treatise on Steam-Boiler Incrustation and Meth¬ 
ods for Preventing Corrosion and the Formation of Scale: 
By Charles T. Davis. Illustrated by 65 engravings. 8vo. 
DAVIS.—The Manufacture of Paper: 

Being a Description of the various Processes for the Fabrication, 
Coloring and Finishing of every kind of Paper, Including the Dif¬ 
ferent Raw Materials and the Methods for Determining their Values, 
the Tools, Machines and Practical Details connected with an intelli¬ 
gent and a profitable prosecution of the art, with special reference to 
the best American Practice. To which are added a History of Pa¬ 
per, complete Lists of Paper-Making Materials, List of American 
Machines, Tools and Processes used in treating the Raw Materials, 
and in Making, Coloring and Finishing Paper. By Charles T. 
Davis. Illustrated by 156 engravings. 608 pages, 8vo. #6.00 
DAVIS.—The Manufacture of Leather: 

Being a Description of all the Processes for the Tanning and Tawing 
with Bark, Extracts, Chrome and all Modern Tannages in General 
Use, and the Currying, Finishing and Dyeing of Every Kind of Leather; 
Including the Various Raw Materials, the Tools, Machines, and all 
Details of Importance Connected with an Intelligent and Profitable 
Prosecution of the Art, with Special Reference to the Best American 
Practice. To which are added Lists of American Patents (1884—1897) 
for Materials, Processes, Tools and Machines for Tanning, Currying, 
etc. By Charles Thomas Davis. Second Edition, Revised, and 
in great part Rewritten. Illustrated by 147 engravings and 14 Sam¬ 
ples of Quebracho Tanned and Aniline Dyed Leathers. 8vo, cloth, 

712 pages. Price.$12.50 

DAWIDOWSKY—BRANNT.—A Practical Treatise on the 
Raw Materials and Fabrication of Glue, Gelatine, Gelatine 
Veneers and Foils, Isinglass, Cements, Pastes, Mucilages, 
etc.: 

Based upon Actual Experience. By F. Dawidowsky, Teclnvcal 
Chemist. Translated from the German, with extensive addition-, 
including a description of the most Recent American Processe-. 1 y 
William T. Brannt. 2d revised edition, 350 pages. (1905.) 

Price. $3.00 

DE GRAFF.—The Geometrical Stair-Builders’ Guide: 

Being a Plain Practical System of Hand-Railing, embracing all it« 
necessary Details, and Geometrically Illustrated by twenty-two Stee 
Engravings; together with the use of the most approved pnncit>i<* 
of Practical Geometry By Simon De Graff. Architect (.x-. 




HENRY CAREY BAIRD & CO.’S CATALOGUE. 


i) 


DE KONINCK—DIETZ.—A Practical Manual of Chemical 
Analysis and Assaying: 

As applied to the Manufacture of Iron from its Ores, and to Cast Iron, 
Wrought Iron, and Steel, as found in Commerce. By L. L. Dfi 
Koninck, Dr. Sc., and E. Dietz, Engineer. Edited with Notes, by 
Robert Mallet, F. R. S., F. S. G., M. I. C. E., etc. America® 
Edition, Edited with Notes and an Appendix on Iron Ores, by A. A. 
Fesquet, Chemist and Engineer. i2mo. . . . $1.00 

DUNCAN.—Practical Surveyor’s Guide: 

Containing the necessary information to make any person of com} 
mon capacity, a finished land surveyor without the aid of a teacher. 
By Andrew Duncan. Revised. 72 engravings, 214pp. i2mo. $1.50 
DUPLAIS.—A Treatise on the Manufacture and Distillation 
of Alcoholic Liquors: 

Comprising Accurate and Complete Details in Regard to Alcohol 
from Wine, Molasses, Beets, Grain, Rice, Potatoes, Sorghum, Aspho 
del, Fruits, etc.; with the Distillation and Rectification of Brandy, 
Whiskey, Rum, Gin, Swiss Absinthe, etc., the Preparation of Aro¬ 
matic Waters, Volatile Oils or Essences, Sugars, Syrups, Aromatic 
Tinctures, Liqueurs, Cordial Wines, Effervescing Wines, etc., the 
Ageing of Brandy and the improvement of Spirits, with Copious 
Directions and Tables for Testing and Reducing Spirituous Liquors, 
etc..# etc. Translated and Edited from the French of MM. Duplais, 
By M. McKennie, M. D. Illustrated 743 pp. 8vo. $ 15.00 
DYER AND COLOR-MAKER’S COMPANION : 

Containing upwards of two hundred Receipts for making Colors, on 
the most approved principles, for all the various styles and fabrics now 
in evistence; with the Scouring Process, and plain Directions for 
Preparing, Washing-off, and Finishing the Goods. i2mo. $1 00 
EIDHERR.—The Techno-Chemical Guide to Distillation; 

A Hand-Book for the Manufacture of Alcohol and Alcoholic Liquors, 
including the- Preparation of Malt and Compressed Yeast. Edited 
from the German of Ed. Eidherr. 

EDWARDS.—A Catechism of the Marine Steam-Engine, 

For the use of Engineers, Firemen, and Mechanics. A Practical 
Work for Practical Men. By Emory Edwards, Mechanical Engi¬ 
neer. Illustrated by sixty-three Engravings, including examples of 
the most modern Engines. Third edition, thoroughly revised, with 
much additional matter. i2mo. 414 pages ... $2 00 

EDWARDS.—Modern American Locomotive Engines, 

Their Design, Construction and Management. By Emory EDWARDS# 
Illustrated i2mo. ...••••• $2.00 

EDWARDS.—The American Steam Engineer: 

Theoretical and Practical, with examples of the late A and most ap¬ 
proved American practice in the design and construction of Steam 
Engines and Boilers. For the use of engineers, machinists, boiler- 
takers, and engineering students. By Emory Edwards. Fully 
illustrated. 419 pages. i2mo. .... $2.00 






12 


HENRY CAREY BAIRD & CO.’S CATALOGUE. 


EDWARDS.—Modern American Marine Engines, Boilers, and 
Screw Propellers, 

Their Design and Construction. Showing the Present Practice ot 
the most Eminent Engineers and Marine Engine Builders in the 
United States. Illustrated by 30 large and elaborate plates. 4to. $ 3.00 
EDWARDS.—The Practical Steam Engineer’s Guide 

In the Design, Construction, and Management of American Stationary, 
Portable, and Steam Fire-Engines, Steam Pumps, Boilers, Injector^ 
Governors, Indicators, Pistons and Rings, Safety Valves and Steam 
Gauges. For the use of Engineers, Firemen, and Steam Users. B) 
Emory Edwards. Illustrated by 119 engravings. <120 pages. 

i2mo.#2.00 

EISSLER.—The Metallurgy of Silver : 

A Practical Treatise on the Amalgamation, Roasting, and Lixiviation 
of Silver Ores, including the Assaying, Melting, and Refining of 
Silver Bullion. By M. Eissler. 124 Illustrations. 336 pp. 

i2mo.$4-25 

ELDER.—Conversations on the Principal Subjects of Political 
Economy. 

By Dr. William Elder. 8vo. ... . $1.50 

ELDER.—Questions of the Day, 

Economic and Social. By Dr. William Elder. 8vo. . $3.00 

ERNI AND BROWN.—Mineralogy Simplified. 

Easy Methods of Identifying Minerals, including Ores, by Means of 
the Blow-pipe, by Flame Reactions, by Humid Chemical Analysis, 
and by Physical Tests. By Henri Erni, A. M., M. D. Fourth Edi¬ 
tion, revised, re-arranged and with the addition of entirely new matter, 
including Tables for the Determination of Minerals by Chemical and 
Pyrognostic Characters, and by Physical Characters. By Amos P. 
Brown, E. M.,Ph. D. 464 pp.. illustrated by 123 engravings, pocket- 
book form, full flexible morocco, gilt edges . . . $2.50 

FAIRBAIRN. The Principles of Mechanism and Machinery 
of Transmission : 

Comprising the Principles of Mechanism, Wheels, and Pulleys, 
Strength and Proportion of Shafts, Coupling of Shafts, and Engag¬ 
ing and Disengaging Gear. By Sir William Fairbairn, Bart. 
C. E. Beautifully illustrated by over 150 wood-cuts. In one 
volume, i2mo.#2.00 

FLEMING.—Narrow Gauge Railways in America : 

A Sketch of their Rise, Progress, and Success. Valuable Statistics 
as to Grades, Curves, Weight of Rail, Locomotives, Cars, etc. By 
Howard Fleming. Illustrated, 8vo. $1.00 

FORSYTH.—Book of Designs for Headstones, Mural, and 
other Monuments : 

Containing 78 Designs. By James Forsyth, With an Introduction 
by Charles Boutell, M. A. 4to., cloth . . . $3.50 

FRIEDBERG. Utilization of Bones by Chemical Means* 
especially the Modes of Obtaining Fat, Glue, Manures* 
Phosphorus and Phosphates. 

Illustrated. 8vo. (In preparation.) 





HENRY CAREY BAIRD & CO.’S CATALOGUE. 


13 


FRANKEL—HUTTER.—A Practical Treatise on the Mann* 
facture of Starch, Glucose, Starch-Sugar, and Dextrine: 

Based on the German of Ladislaus Von Wagner, Professor in the 
Royal Technical High School, Buda-Pest, Hungary, and other 
authorities. By Julius Frankel, Graduate of the Polytechnic 
School of Hanover. Edited by Robert Hutter, Chemist, Practical 
Manufacturer of Starch-Sugar. Illustrated by 58 engravings, cover¬ 
ing every branch of the subject, including examples of the most 
Recent and Best American Machinery. 8vo., 344 pp. 

GARDNER.—The Painter’s Encyclopaedia: 

Containing Definitions of all Important Words in the Art of Plain 
and Artistic Painting, with Details of Practice in Coach, Carriage, 
Railway Car, House, Sign, and Ornamental Painting, including 
Graining, Marbling, Staining, Varnishing, Polishing, Lettering, 
Stenciling, Gilding, Bronzing, etc. By Franklin B. Gardner. 

158 Illustrations. i2mo. 427 pp.$2.oG 

GARDNER.—Everybody’s Paint Book: 

A Complete Guide to the Art of Outdoor and Indoor Painting. 38 
illustrations. i2mo, 183 pp.. . $1.00 

GEE.—The Jeweller’s Assistant in the Art of Working in 
Gold: 

A Practical Treatise foi Masters and Workmen. !2mo. . $3.00 

GEE.—The Goldsmith’s Handbook : 

Containing full instructions for the Alloying and Working of Gold, 
including the Art of Alloying, Melting, Reducing, Coloring, Col¬ 
lecting, and Refining; the Processes of Manipulation, Recovery of 
Waste; Chemical and Physical Properties of Gold; with a New 
System of Mixing its Alloys; Solders, Enamels, and other Useful 
Rules and Recipes. By George E. Gee. i2mo. , . $1.25 

GEE.—The Silversmith’s Handbook : 

Containing full instructions for the Alloying and Working of Silver, 
including the different modes of Refining and Melting the Metal; its 
Solders; the Preparation of Imitation Alloys; Methods of Manipula¬ 
tion; Prevention of Waste; Instructions for Improving and Finishing 
the Surface of the Work; together with other Useful Information and 
Memoranda. By George E. Gee. Illustrated. i2mo. Si.25 
GOTHIC ALBUM FOR CABINET-MAKERS: 

Designs for Gothic Furniture. Twenty-three plates. Oblong # 1 - 5 ° 
GRANT.—A Handbook on the Teeth of Gears : 

Their Curves, Properties, and Practical Construction. By George 
B. Grant. Illustrated. Third Edition, enlarged. 8vo. #1.00 
GREENWOOD.—Iron and Steel: 

Vol. I. Iron : Its Sources, Properties, and Manufacture. By Will¬ 
iam Henry Greenwood. Revised and Re-written by A. Hum¬ 
boldt .''Exton. 255pp. Illustrated i2mo. . . . #i.oo 

Vol. II. Meel * Its Varieties, Properties, and Manufacture By 
William Henry Greenwood. Revised and Re-written by A. 
Humboldt bEXTON. 254pp. Illustrated. i2mo. . . £1.00 





14 


HENRY CAREY BAIRD & CO.’S CATALOGUE 


GREGORY.—Mathematics for Practical Men : 

Adapted to the Pursuits of Surveyors, Architects, Mechanics, and 
Civil Engineers. By Olinthus Gregory. 8vo., plates 

GRISWOLD.—Railroad Engineer’s Pocket Companion for thi 
Field: 

Comprising Rules for Calculating Deflection Distances and Angles, 
Tangential Distances and Angles, and all Necessary Tables for En 
gineers; also the Art of Levelling from Preliminary Survey to the 
Construction of Railroads, intended Expressly for the Young En- 
gineer, together with Numerous Valuable Rules and Examples. By 

W. Griswold. i2mo., tucks.# 1 - 5 ° 

GKUNER.—Studies of Blast Furnace Phenomena: 

By M. L. Gruner, President of the General Council of Mines oi 
France, and lately Professor of Metallurgy at the Ecole des Mines. 
Translated, with the author’s sanction, with an Appendix, by L. D. 
B. Gordon, F. R. S. E., F. G. S. 8vo. . . . #2.50 

Hand-Book of Useful Tables for the Lumberman, Farmer and 
Mechanic: 

Containing Accurate Tables of Logs Reduced to Inch Board Meas* 
ure, Plank, Scantling and Timber Measure; Wages and Rent, by 
Week or Month; Capacity of Granaries, Bins and Cisterns; Land 
Measure, Interest Tables, with Directions for Finding the Interest on 
any sum at 4, 5, 6, 7 and 8 per cent., and many other Useful Tables. 

32 mo., boards. 186 pages. .25 

HASERICK.—The Secrets of the Art of Dyeing Wool, Cotton, 
and Linen, 

Including Bleach'lr.g and Coloring Wool and Cotton Hosiery and 
Random Yarns. A Treatise based on Economy and Practice. By 
E. C. Haserick. Illustrated by 323 Dyed Patterns of the Yarn\ 
or Fabrics. 8vo. ........ 

HATS AND FELTING : 

A Practical Treatise on their Manufacture. By a Practical Hatter, 
Illustrated by Drawings of Machinery, etc. 8vo. . . $1.00 

HERMANN.—Painting on Glass and Porcelain, and Enamel 
Painting: 

A Complete Introduction to the Preparation of all the Colors and 
Fluxes Used for Painting on Glass, Porcelain, Enamel, Faience and 
Stoneware, the Color Pastes and Colored Glasses, together with a 
Minute Description ot the Firing ot Colors and Enamels, on th« 
Basis of Personal Practical Experience of the Art up to Date. 18 
illustrations. Second edition.. $4.00 

HAUPT.—Street Railway Motors: 

With Descriptions and Cost of Plants and Operation of the Various 
Systems now in Use. - . . . $ 1 - 5 ° 






HENRY CAREY BAIRD & CO.’S CATALOGUE. 


*5 


HAUPT.-A Manual of Engineering Specifications and Con¬ 
tracts. 

By Lewis M. Haupt, C. E. Illustrated with numerous maps. 
328pp. 8vo.. 00 

HAUPT.—The Topographer, His Instruments and Methods. 
By Lewis M. Haupt, A. M., C. E. Illustrated with numerous 
plates, maps and engravings. 247 pp. 8vo. . . . #3.00 

HUGHES.—American Miller and Millwright’s Assistant: 

By William Carter Hughes. i2mo.$1.50 

flULME.—Worked Examination Questions in Plane Gecmet 
rical Drawing : 

For the Use of Candidates for the Royal Military Academy, Wool¬ 
wich; the Royal Military College, Sandhurst; the Indian Civil En¬ 
gineering College, Cooper’s Hill; Indian Public Works and Tele¬ 
graph Departments; Royal Marine Light Infantry; the Oxford and 
Cambridge Local Examinations, etc. By F. Edward Hulme, F. L. 
S., F. S. A., Art-Master Marlborough College. Illustrated by 300 

examples. Small quarto. $1 00 

JERVIS.—Railroad Property: 

A Treatise on the Construction and Management of Railways; 
designed to afford useful knowledge, in the popular style, to the 
holders of this class of property ; as well as Railway Managers, Offi¬ 
cers, and Agents. By John B. Jervis, late Civil Engineer of the 
Hudson River Railroad, Croton Aqueduct, etc. i2mo., cloth $i.c;o 
KEENE.—A Hand-Book of Practical Gauging: 

For the Use of Beginners, to which is added a Chapter on Distilla¬ 
tion, describing the process in operation at the Custom-House for 
ascertaining the Strength of Wines. By James B. Keene, of H. M. 
Customs. 8vo. . . . . . . . . |l cc 

KELLEY.—Speeches, Addresses, and Letters on Industrial and 
Financial Questions: 

By Hon. William D. Kelley, M. C. 544 pages, 8vo. . $ 2 . 50 

KOENIG.—Chemistry Simplified: 

A Course of Lectures on the Non-Metals Based upon the Natural 
Evolution of Chemistry. Designed Primarily for Engineers. By 
George Augustus Koenig, Ph. D., A. M., E. M., Professor of 
Chemistry, Michigan College of Mines, Houghton. Illustrated by 
103 Original Drawings. 449 pp. i2mo., (1906). . . $2.25 

KEMLO.—Watch-Repairer’s Hand-Book: 

Being a Complete Guide to the Young Beginner, in Taking Apart, 
Putting Together, and Thoroughly Cleaning the English Lever and 
other Foreign Vv^atches, and all American Watches. By F. Kemlo, 
Practical Watchmaker. With Illustrations. I2ma $125 






t6 HENRY CAREY BAIRD & CO.’S CATALOGUE. 


KENTISH.—A Treatise on a Box of Instruments, 

And the Slide Rule; with the Theory of Trigonometry and Loga 
rithms, including Practical Geometry, Surveying, Measuring of Tim¬ 
ber, Cask and Malt Gauging, Heights, and Distances. By Thoma? 
Kentish. In one volume. i2mo. .... $i.oc 
KERL.— The Assayer’s Manual: 

An Abridged Treatise on the Docimastic Examination of Ores, and 
Furnace and other Artificial Products. By Bruno Kerl, Professor 
in the Royal School of Mines. Translated from the German by 
William T. Brannt. Second American edition, edited with Ex¬ 
tensive Additions by F. Lynwood Garrison, Member of the 
American Institute of Mining Engineers, etc. Illustrated by 87 en¬ 
gravings. 8vo. (Third Edition in preparation.) 

KICK.—Flour Manufacture. 

A Treatise on Milling Science and Practice. By Frederick Kick 
Imperial Regierungsrnth, Professor of Mechanical Technology in tht 
imperial German Polytechnic Institute, Prague. Translated from 
the second enlarged and revised edition with supplement by H. H. 
P. Powles, Assoc. Memb. Institution of Civil Engineers. Illustrated 
with 28 Plates, and 167 Wood-cuts. 367 pages. 8vo. . #10.00 

KINGZETT.—The History, Products, and Processes of tho 
Alkali Trade : 

including the most Recent Improvements. By Charles Thomas 
V ''^7prr Consulting Chemist. With 23 illustrations. 8vo. #2.50 
KIRK.—The Cupola Furnace: 

A Practical Treatise on the Construction and Management of Foundry 
Cupoias. By Edward Kirk, Practical Moulder ami Melter, Con* 


suiting Expert in Melting. Illustrated by 78 engravings. Second 
Edition, revised and enlarged. 450 pages. 8vo. 1903. #3.50 

LANDRIN.—A Treatise on Steel: 

Comprising its Theory, Metallurgy. Properties, Practical Working, 
and Use. By M. H. C. Landrin, Jr. From the f rench, by A. A. 
Fesquet. i2mo. $ 2 . 0Q 


LANGBEIN.—A Complete Treatise on the Electro-Deposi. 
tion of Metals: 

Comprising Electro-Plating and Galvanoolastic Operations, the De¬ 
position of Metals by the Contact a^d Immersion Processes, the Color¬ 
ing of Metals, the Methods of Grinding and P< long, as well as 
Description of the Voltaic Cells, Dynamo-Electric Machines, Ther- 
mopyles, and of the Materials and Processes Used in Every Depart¬ 
ment of the Art. 1 ranslated from the Fifth German Ldition of 
Dr. George 1 angbein, 1 roprietor of a Manufactory for Chemical 
Products, Machines, Apparatus and Utensils for Electro-! Inters, and 
of an Electro-Plating Establishment in Leipzig. With Additions by 
William T. Brannt, Ediiot of ‘ The Techno-Chemical Receipt 
Book.” Pixth Edition, Revised and Enlarged. Illustrated by 163 
Engravings, 8vo , 725 pages (1909) . . . . . #4 00 

LEHNER.—The Manufacture of Ink: 

Comprising the Raw Materials, and the Preparation of Writing, 
Copying and Hektograph Inks, Safety Inks, Ink Extracts and Pow. 
ders, etc. Translated from the German of Sigmund I.miv'r, with 
additions by William T. Brannt. Illustrated. 12m.. S2.00 





HENRY CAREY BAIRD & CO.’S CATALOGUE. 17 


LARKIN.—The Practical Brass and Iron Founder’s Guide.* 

A Concise Treatise on Brass Founding, Moulding, the Metals and 
their Alloys, etc.; to which are added Recent Improvements in the 
Manufacture of Iron, Steel by the Bessemer Process, etc., etc. Bj 
James Larkin, late Conductor of the Brass Foundry Department u 
Reany, Neafie & Co.’s Penn Works, Philadelphia. New edition* 
revised, with extensive additions. 414 pages. 121110. . $2.5® 

LEROUX.—A Practical Treatise on the Manufacture of 
Worsteds and Carded Yarns : 

Comprising Practical Mechanics, with Rules and Calculations applied 
to Spinning; Sorting, Cleaning, and Scouring Wools; the English 
and French Methods of Combing, Drawing, and Spinning Worsteds, 
and Manufacturing Carded Yarns. Translated from the French of 
Charles Leroux, Mechanical Engineer and Superintendent of a 
Spinning-Mill, by Horatio Paine, M. D., and A. A. Fesquet, 
Chemist and Engineer. Illustrated by twelve large Plates. To which 
is added an Appendix, containing Extracts from the Reports of th# 
International Jury, and of the Artisans selected by the Commttte* 
appointed by the Council of the Society of Arts, London, on Woole* 
and Worsted Machinery and Fabrics, as exhibited in the Paris Uni* 
versai Exposition, 1867. 8vo. ..... $4.00 

LEFFEL.—The Construction of Mill-Dams ; 

Comprising also the Budding of Race and Reservoir Embankments 
and Head-Gates, the Measurement of Streams, Gauging of Water 
Supply, etc. By James Leffel & Co. Illustrated by 58 engravings. 
8vo. ......... (Scarce.) 

LESLIE.—Complete Cookery: 

Directions for Cookery in its Various Branches. By Miss Leslie. 
Sixtieth thousand. Thoroughly revised, with the addition of New 
Receipts. i2ino. ... • ^ I - 5 ° 

LE VAN —The Steam Engine and the Indicator: 

Their Origin and Progressive Development; including the Most 
Recent Examples of Steam and Gas Motors, together with the lndi 
cator, its Principles, its Utility, and its Application. By William 
Barnet Le Van. Illustrated by 205 Engravings, chiefly of lndi- 
cator-Cards. 469 pp. 8vo. ...... $2.00 

LIEBER.—Assayer’s Guide : 

Or, Practical Directions to Assayers, Miners, and Smelters, for the 
Tests and Assays, by Heat and by Wet Processes, lor the Ores of a 1 
tb principal Metals, of Gold and Silver Coins ami Alloy- and of 
Coal, etc. By Oscar M. Lif.rer. Revised. 283 pp. ? 

Lockwood’s Dictionary of Terms : 

Used in the Practice of Mechanical Engineering, embracing those 
Current in the Drawing Office, Pattern Shop. Foundry, Fitting, Turn¬ 
ing Smith’s and Boiler Shops, etc., etc., comprising upwards of Six 
Thousand Definitions. Edited by a Foreman Pattern Maker, authoi 
M “ Patter Making.” 417 PP* I2mo - ^ f75 




l8 


HENRY CAREY BAIRD & CO.’S CATALOGUE 


LUKIN.—The Lathe and Its Uses: 

Or instruction in the Art of Turning Wood and Metal. Including 
a Description of the Most Modern Appliances for the Ornamentation 
of Plane and Curved Surfaces, an Entirely Novd Form of Lathe 
for Eccentric and Rose-Engine Turning; A Lathe and Planing 
Machine Combined; and Other Valuable Matter Relating to the 
Art. Illustrated by 462 engravings. Seventh edition. 315 pages. 
Svo.£4.25 

IfiAIN and BROWN.—Questions on Subjects Connected with 
the Marine Steam-Engine; 

And Examination Papers; with Hints for their Solution. By 
Thomas J. Main, Professor of Mathematics, Royal Naval College, 
and Thomas Brown, Chief Engineer, R. N. 121110., cloth . 

MAIN and BROWN.—The Indicator and Dynamometer: 

With their Practical Applications to the Steam-Engine. By Thomas 
J. Main, M. A. F. R., Ass’t S. Professor Royal Naval College, 
Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer 
R. N., attached to the R. N. College. Illustrated. Svo. . 

IfiAIN and BROWN.—The Marine Steam-Engine. 

By Thomas J. Main, F. R. Ass’t S. Mathematical Professor at the 
Royal Naval College, Portsmouth, and Thomas Brown, Assoc. 
Inst. C. E., Chief Engineer R. N. Attached to the Royal Naval 
College. With numerous illustrations. 8vo. 

MAKINS.—A Manual of Metallurgy: 

By George Hogarth Makins. ioo engravings. Second edition 
rewritten and much enlarged. i2mo. 592 pages 

MARTIN.—Screw-Cutting Tables, for the Use of Mechanic*) 
Engineers : 

Showing the Proper Arrangement of Wheels for Cutting the Threads 
of Screws of any Required Pitch; with a Table for Making the Uni¬ 
versal Gas-Pipe Thread and Taps. By W. A. Martin, Engineer. 

8vo.. .50 

MICHELL.—Mine Drainage: 

Being a Complete and Practical Treatise on Direct-Acting Under 
rrt und Steam Pumping Machinery. With a Description of a large 
number of the best known Engines, their General Utility and i.he 
Special Sphere of their Action, the Mode of their Application, and 
their Merits compared with other Pumping Machinery. By STEPHEN 
Michf.i.L. Illustrated by 247 engravings. 8vo., 369 pages. $1250 
MOLESWORTH. — Pocket-Book of Useful Formulae and 
Memoranda for Civil and Mechanical Engineers. 

By Guilford L. Molesworth, Member of the Institution of Civil 
Engineers, Chief Resident Engineer of the Ceylon Railway. Full- 
bound in Pocket-book form.#1 00 







*9 


nENRY CAREY BAIRD & CO.’S CATALOGUE. 


MOORE.—The Universal Assistant and the Complete 
chanic; 

Containing over one million Industrial Facts, Calculations, Receipts, 
Processes, Trades Secrets, Rules, Business Forms, Legal Items, Etc., 
in every occupation, from the Household to the Manufactory. By 
R. Moore. Illustrated by 500 Engravings. i2mo. . $2.50 

MORRIS.—Easy Rules for the Measurement of Earthworks: 
By means of the Prismoidal Formula. Illustrated with Numerou? 
Wood-Cuts, Problems, and Examples, and concluded by an Exten 
sive Table for finding the Solidity in cubic yards from Mean Areas. 
The whole being adapted for convenient use by Engineers, Surveyors 
Contractors, and others needing Correct Measurements of Earthwork 

By Elwood Morris, C. E. 8vo.. $1.5* 

MAUCHLINE.—The Mine Foreman’s Hand-Book 

Of Practical and Theoretical Information on the Opening, Venti¬ 
lating, and Working of Collieries. Questions and Answers on Prac¬ 
tical and Theoretical Coal Mining. Designed to Assist Students and 
Others in Passing Examinations for Mine Foremanships. By 
Robert Mauchline. 3d Edition. Thoroughly Revised and En¬ 
larged by F. Ernest Brackett. 134 engravings, 8vo. 378 pages. 

( x 9 ° 5 ).. $ 3-7 5 

NAPIER.—A System of Chemistry Applied to Dyeing. 

By James Napier, F. C. S. A New and Thoroughly Revised Edl 
tion. Completely brought up to the present state of the Science, 
including the Chemistry of Coal Tar Colors, by A. A. Fesquet, 
Chemist and Engineer. With an Appendix on Dyeing and Calico 
Printing, as shown at the Universal Exposition, Paris, 1867. Ulus 
trated. 8vo. 422 pages ....... $ 2.00 

NEVILLE. — Hydraulic Tables, Coefficients, and Formula, foi 
finding the Discharge of Water from Orifices, Notches. 
Weirs, Pipes, and Rivers: 

Third Edition, with Additions, consisting of New Formulae for the 
discharge from Tidal and Flood Sluices and Siphons; general infor¬ 
mation on Rainfall, Catchment-Basins, Drainage, Sewerage, Water 
Supply for Towns and Mill Power. Bv Tohn Neville. C. E. M. R 
I. A.; Fellow of the Royal Geological Society of Ireland. Thiel 
I2mo. ......... Scarce 

IEWBERY.— Gleanings from Ornamental Art of every 
style: 

Drawn from Examples in the British, South Kensington, Indian, 
Crystal Palace, and other Museums, the Exhibitions of 1851 and 
1862, and the best English and Foreign works. In a series of 100 
exquisitely drawn Plates, containing many hundred examples. B| 
Robert Newbery. 4to. ...... (Scarce. J 

NICHOLLS. —The Theoretical and Practical Boiler-Maker an# 
Engineer’s Reference Book: 

Containing a variety of Useful Information for Employers of Labor 
Foremen a’vl Working Boiler-Makers. Iron, Copper, and Tinsmith* 






JO HENRY CAREY BAIRD & CO.’» CATALOGUE. 


Draughtsmen, Engineers, the General Steam-using Public, and for the 
Use of Science Schools and Classes. By Samuel NlCHOLLS. I 11 u» 
trated by sixteen plates, 121110. ..... $2.$c 

NICHOLSON.—A Manual of the Art of Bookbinding: 
Containing lull instructions in the different Branches of Forwarding* 
Gliding, and Finishing. Also, the Art of Marbling Book-edges and 
Paper. By James B. Nicholson. Illustrated. i2mo., cloth $2.25, 
NICOLLS.—The Railway Builder: 

A Hand-Book lor Estimating the Probable Cost of American Rail¬ 
way Construction and Equipment. By WlLI.lAM J. Nicolls, Civil 
Engineer. Illustrated, full bound, pocket-book form . Scarce 

NORMANDY.—The Commercial Handbook of Chemical An* 
alysis: 

Or Practical Instructions for the Determination of the Intrinsic ot 
Commercial Value of Substances used in Manufactures, in Trades, 
and in the Arts. By A. Normandy. New Edition, Enlarged, and 
to a great extent rewritten. By Henry M. Noad, Ph.D., F.R.S. V 
thick i2mo. ......... Scarce 

NORRIS.—A Handbook fcr Locomotive Engineers and Ma 
chinists: 

Comprising the Proportions and Calculations for Constructing Loco¬ 
motives; Manner of Setting Valves; Tables cf Squares, Cubes, Areas* 
etc., etc. By Septimus Norris, M. E. New edition. Illustrated^ 

!2mo.#1.50 

NYSTRGM.—A New Treatise on Elements of Mechanics: 
Establishing Strict Precision in the Meaning of Dynamical Terms- 
accompanied with an Appendix on Duodenal Arithmetic and Me 
trologv. By John W. Nystrom, C. E. Illustrated. 8vo. 
NYSTJRQM.—On Technological Education and the Construc¬ 
tion of Ships and Screw Propellers: 

For Naval and Marine Engineers. By John V/. Nystrom. - 
Acting Chief Engineer, U. S. N. Second edition, revised, with addi 
tional matter. Illustrated by seven engravings, iznio. $1.25 

O’NEILL.—A Dictionary of Dyeing and Calico printing: 
Containing a brief account of ai! Hie Substances and Piocesses ’t 
use in the Art of Dyeing and Printing Textile Fabrics ; with Practl'ci 
Receipts and Scientific Information Bv Chafles O’Neill, Analy¬ 
tical Chemist. To which is added an Essay on Coal Tar Colors ano 
their application to Dyeing and Calico Printing. By A. A. Fesquet, 
Chemist and Engineer. With an appendix on Dyeing and Calico 
Printing, as shown at the Universal Exposition, Paris, 1867 8vo.„ 

49I pages $2.00 

ORTON.—Underground Treasures*. 

How and Where to bind 1 iicm. A Rev for the Ready Determination 
of ail the Useful Minerals within the United States. By James 
a.M., Late Professor ot Natural ,r - rv Vassar College, 
author of the “ Andes and the Amazon,” etc A New Edi- 
with An Appendix on Ore Deposits and besting Minerals (1901). 
illustrated . . cr> 





HENRY CAREY BAIRD & CO/S CATALOGUE. 


21 


OSBORN.—The Prospector’s Field Book and Guide. 

In the Search l'or and ihe Easy Determination of Ores and Other 
Useful Minerals. By Prof. H. S. Osborn, LL. D. Illustrated by 66 
Engravings. Seventh Edition. Revised and Enlarged. 379 pages, 
i2mo. (March, 1907).$i. 5 o 

DSBORN—A Practical Manual of Minerals, Mines and Mm 
ing: 

Comprising the Physical Properties, Geologic Positions, Local Occur 
rence and Associations of the Useful Minerals; their Methods of 
Chemical Analysis and Assay ; together with Various Systems of Ex¬ 
cavating and Timbering, Brick and Masonry Work, during Driving, 
Lining, Bracing and other Operations, etc. By Prof. H. S. Osborn, 
LL. D., Author of “The Prospector’s Field-Book and Guide.” 171 
engravings. Second Edition, revised. 8vo. . . . $4.50 

OVERMAN.—Thu Manufacture of Steel: 

Containing the Practice and Principles of Working and Making Steel. 
A Handbook for Blacksmiths and Workers in Steel and Iron, Wagon 
Makers, Die Sinkers, Cutlers, and Manufacturers of Files and Hard¬ 
ware, of Steel and Iron, and for Men of Science and Art. By 
Frederick Overman, Mining Engineer, Author of the “ Manu¬ 
facture of lion,” etc. A new, enlarged, and revised Edition. By 
A. A. Fesquet, Chemist and Engineer. i2mo. . . $1.50 

OVERMAN.—The Moulder’s and Founder’s Pocket Guide : 

A Treatise or. Mouldingand Founding in Green-sand, Dry sand, Loam, 
and Cement; the Moulding of Machine Frames, Mill-gear, Hollow- 
ware, Ornaments, Trinkets, Bells, and Statues; Description of Moulds 
for Iron, Brcnze, Brass, and other Metals; Plaster of Paris, Sulphur, 
Wax, etc.; the Construction of Melting Furnaces, the Melting and 
Founding of Metals ; the Composition of Alloys and their Nature, 
etc., etc. By Frederick Overman, M. E. A new Edition, to 
which is added a Supplement on Statuary and Ornamental Moulding, 
Ordnance, Malleable Iron Castings, etc. By A. A. Fesquet, Chen*- 
ist and Engineer. Illustrated by 44 engravings. 12mo. . $2.0C 

PAINTER, GILDER, AND VARNISHER’S COMPANION. 
Comprising the Manufacture and l est of Pigments, the Arts of Paint¬ 
ing, Graining, Marbling, Staining, Sign-writing, Varnishing, Glass- 
staining, and Gilding on Glass; together with Coach Painting and 
Varnishing, and the Principles of the Harmony and Contrast of 
Colors. Twenty-seventh Edition. Revised, Enlarged, and in great 
part Rewritten. By William T. Brannt, Editor of “Varnishes, 
Lacquers, Printing Inks and Sealing Waxes.” Illustrated. 395 pp. 

Z2mo. . . #1 50 

PALLETT.—The Miller’s, Millwright’s,and Engineer’s Guide. 
By Henry Pallett. Illustrated. i2mo. . . . $ 2.00 





22 


HENRY CAREY BAIRD & CO.’S CATALOGUE. 


PERCY.—The Manufacture of Russian Sheet-Iron. 

By John Percy, M. D., F. R. S. Paper. ... 25 eta, 

PERKINS.—Gas and Ventilation : 

Practical Treatise on Gas and Ventilation. Illustrated. I2mo. #I. 2 J 
PERKINS AND STOWE.— A New Guide to the Sheet-iron 
and Boiler Plate Roller : 

Containing a Series of Tables showing the Weight of Slabs and Pile* 
to Produce Boiler Plates, and of the Weight of Piles and the Sizes of 
Bars to produce Sheet-iron; the Thickness of the Bar Gauge 
in decimals; the Weight per foot, and the Thickness on the Bar or 
Wire Gauge of the fractional parts of an inch; the Weight per 
sheet, and the Thickness on the Wire Gauge of Sheet-iron of various 
dimensions to weigh 112 lbs. per bundle; and the conversion of 
Short Weight into Long Weight, and Long Weight into Short. 

#1.50 

POSSELT.—Recent Improvements in Textile Machinery Re¬ 
lating to Weaving: 

Giving the Most Modern Points on the Construction of all Kinds 
of Looms, Warpers, Beamers, Slashers, Winders, Spoolers, Reeds, 
Temples, Shuttles, Bobbins, Heddles, Heddle Frames, Pickers, 
Jacquards, Card Stampers, Etc., Etc. By E. A. Posselt. 4to. 
Part I., 6co ills.; Part II., 60c ills. Each part . . . $3.00 

Part III., 615 ills. ........ $7.50 

POSSELT.—Technology of Textile Design: 

The Most Complete Treatise on the Construction and Application 
of Weaves for all Textile Fabrics and the Analysis of Cloth. By E. 
A. Posselt. 1,500 illustrations. 4to. .... $5.00 

POSSELT.—Textile Calculations: 

A Guide to Calculations Relating to the Manufacture of all Kinds 
of Yarns and Fabrics, the Analysis of Cloth, Speed, Power and Belt 
Calculations. By E. A. Posselt. Illustrated. 4to. . $2.00 

REGNAULT.—Elements of Chemistry: 

By M. V. Regnault. Translated from the French by T. Forrest 
Betton, M. D., and edited, with Notes, by James C. Booth, Melter 
and Refiner U. S. Mint, and William L. Faber, Metallurgist and 
Mining Engineer. Illustrated by nearly 700 wood-engravings. Com¬ 
prising nearly 1,500 pages. In two volumes, 8vo., cloth . $6.00 

RICHARDS.—Aluminium : 

Its History, Occurrence, Properties, Metallurgy and Applications, 
including its Alloys. By Joseph W. Richards, A. C M Chemist and 
Practical Metallurgist, Member of the Deutsche Chemische Gesell- 
schaft. Illust. Third edition, enlarged and revised (1895) . #6.00 
RIFFAULT, VERGNAUD, and TOUSSAIHT.—A Practical 
Treatise on the Manufacture of Colors for Painting : 
Comprising the Origin, Definition, and Classification of Colors; the 
Treatment of the Raw Materials; the best Formulae and the Newest. 
Processes for the Preparation of every description of Pigment, and 
the Necessary Apparatus and Directions for its Use; Dryers; ih* 
Testing. Application, and Qualities of Paints, etc., etc. By MM. 
Riffault, Vergnaud, and Toussaint. Revised and Edited by M 



HENRY CAREY BAIRD & CO. S CATALOGUE. 


2 ‘- 


F. Malepeykk. Translated from the French, by A. A- FESQtrsa^ 
Chemist and Engineer. Illustrated by Eighty engravings, In one' 
voi., 8vo., 659 pages $5*°° 

ROPER.—Catechism for Steam Engineers and Electricians: 
Including the Construction and Management of Steam Engines, 
Steam Boilers and Electric Plants. By Stephen Roper. Twenty- 
first edition, rewritten and greatly enlarged by E. R. Keller and 
C. W. Pike. 365 pages. Illustrations. i 8 mo., tucks, gilt. $2.00 
ROPER.—Engineer’s Handy Book: 

Containing Facts, Formulae, fables and Questions on Power, its 
Generation, Transmission and Measurement; Heat, Fuel, and Steam; 
The Steam Boiler and Accessories; Steam Engines and their Parts; 
Steam Engine Indicator; Gas and Gasoline Engines; Materials; 
their Properties and Strength; Together with a Discussion of the Fun¬ 
damental Experiments in Electricity, and an Explanation of Dynamos, 
Motors, Batteries, etc., and Rules for Calculating Sizes of Wires. By 
Stephen Roper. 15th edition. Revised and enlarged by E. R. 
Keller, M. E. and C. W. Pike, B. S. (1899), with numerous illus¬ 
trations. Pocket-book form. Leather.$ 3 * 5 ® 

ROPER.—Hand-Book of Land and Marine Engines: 

Including the Modelling, Construction, Running, and Management 
of Land and Marine Engines and Boilers. With illustrations. By 
Stephen Roper, Engineer. Sixth edition. i2mo.,tvcks, gilt edge. 

# 3-50 

ROPER.—Hand-Book of the Locomotive : 

Including the Construction of Engines and Boilers, and the Construc¬ 
tion, Management, and Running of Locomotives. By Stephen 
Roper. Eleventh edition. i8mo., tucks, gilt edge . $2. 5a 

ROPER.—Hand-Book of Modern Steam FFe-Engines. 

With illustrations. By Stephen Roper, Engineer. Fourth edition, 
i2mo., tucks, gilt edge ....... $3.50 

ROPER.—Questions and Answers for Engineers. 

This little book contains all the Questions that Engineers will be 
asked when undergoing an Examination for the purpose of procuring 
Licenses, and they are so plain that any Engineer or Fireman of or 
dinary intelligence may commit them to memory in a short time. By 
Stephen Roper, Engineer. Third edition . . . $2.00 

ROPER. —Use and Abuse of the Steam Boiler. 

By Stephen Roper, Engineer. Eighth edition, with illustrations. 
i8mo., tucks, gilt edge . . . . . . $2.00 

ROSE.—The Complete Practical Machinist: 

Embracing Lathe Work, Vise Work, Drills and Drilling, Taps and 
Dies, Hardening and Tempering, the Making and Use of Tools 
Tool Grinding, Marking out Work, Machine Tools, etc. By Joshua 
Rose. 39; Engravings. Nineteenth Edition greatly Enlarged with 
New’ and Valuable Matter. i2mo., 504 pages. . . $2.50 

ROSE.—Mechanical Drawing Self-Taught: 

Comprising Instructions in the Selection and Preparation of Drawing 
T nstruments, Elementary Instruction in Practical Mechanical Draw- 




24 HENRY CAREY BAIRD & CO.’S CATALOGUE. 


ing, together with Examples in Simple Geometry and Elementary 
Mechanism, including Screw Threads, Gear Wheels, Mechanical 
Motions, Engines and Boilers. By Joshua Rose, M. E. Illustrated 
by 330 engravings. 8vo , 313 pages .... $4.00 

ROSE.—The Slide-Valve Practically Explained: 

Embracing simple and complete Practical Demonstrations of th. 
operation of each element in a Slide-valve Movement, and illustrat¬ 
ing the effects of Variations in their Proportions by examples care- 
fully selected from the most recent and successful practice. By 
Joshua Rose, M. E. Illustrated by 35 engravings . $1.00 

ROSS.—The Blowpipe in Chemistry, Mineralogy and Geology: 
Containing all Known Methods of Anhydrous Analysis, many Work¬ 
ing Examples, and Instructions for Making Apparatus. By Lieut.- 
Colonel W. A. Ross, R. A., F. G. S. With 120 Illustrations. 
i2mo. .......... $2.00 

SHAW.—Civil Architecture : 

Being a Complete Theoretical and Practical System of Building, con¬ 
taining the Fundamental Principles of the Art. By Edward Shaw, 
Architect. To which is added a Treatise on Gothic Architecture, etc. 
By Thomas W. Sili.oway and George M. Harding, Architects. 
The whole illustrated by 102 quarto plates finely engraved on copper. 
Eleventh edition. 4to. ....... #6.00 

SHUNK.—A Practical Treatise on Railway Curves and Loca 
tion, for Young Engineers. 

By W. F. Shunk, C. E. 121110. F ull bound pocket-book form $2.00 

SLATER.—The Manual of Colors and Dye Wares. 

By J. W. Slater. i2mo.$3.00 

SLOAN.—American Houses : 

A variety of Original Designs for Rural Buildings. Illustrated by 
26 colored engravings, with descriptive references. By Samuel 

Sloan, Architect. 8vo. . .75 

SLOAN.—Homestead Architecture: 

Containing Forty Designs for Villas, Cottages, and Farm-houses, with 
Eusays on Style, Construction, Landscape Gardening, Furniture, etc., 
etc. Jllustrated by upwards of 200 engravings. By Samuel Sloan, 
Architect. 8vo. ... .... $2.50 

SLOANE.—Ho.re Experiments m Science. 

By T. O’Conor Slcane, E. M., A. M., Fk. D. Illustrated by 91 
engravings. i2mo.#1.00 

SMEATON.—Builder’s Pockti'Companion: 

Containing the Elements of Building, Surveying, and Architecture; 
with Practical Rules and Instructions connected with the subject. 
By A. C. Smeaton, Civil Engineer, etc. i2mo. 

SMITPL—A Manual of Political Economy. 

By E. Peshine Smith. A New Edition, to which is added a full 
Index, nmo. . .$1 2c 





HENRY CAREY BaIRD & CO/S CATALOGUE. 


25 


SMITH. —Parks and Pleasure-Grounds: 

Or Practical Notes on Country Residences, Villas, Public Parks, and 
Gardens. By Charles H. J. Smith, Landscape Gardener and 
Garden Architect, etc., etc. i2mo. .... $ 2.00 

SMITH.—The Dyer’s Instructor: 

Comprising Practical Instructions in the Art of Dyeing Silk, Cotton, 
Wool, and Worsted, and Woolen Goods; containing nearly 800 
Receipts. To which is added a Treatise on the Art of Padding; an<^ 
the Printing of Silk Warps, Skeins, and Handkerchiefs, and the' 
v nious Mordants and Colors for the different styles of such work, 
B/ David Smith, Pattern Dyer. 121110. . . $1.00 

SMYTH.—A Rudimentary Treatise on Coal and Coal-Mining. 
By Warrington W. Smyth, M. A., F. R. G., President R. G. S, 
of Cornwall. Fifth edition, revised and corrected. With numer* 

ous illustrations. i2mo. .$1.40 

SNIVELY.—Tables for Systematic Qualitative Chemical Anal, 
ysis. 

By John H. Snivei.y, Phr. D. 8 vo. .... $1.00 

SNIVELY.—The Elements of Systematic Qualitative v, hemical 
Analysis : 

A Hand-book for Beginners. By John H. SNIVELY, Phr. D. i6mo. 

$ 2.00 

STOKES.—The Cabinet Maker and Upholsterer’s Companion: 

Comprising the Art of Drawing, as applicable to Cabinet Work; 
Veneering, Inlaying, and Buhl-Work; the Art of Dyeing and Stain 
ing Wood, Ivory, Bone, Tortoise-Shell, etc. Directions for Lacker- 
ing, Japanning, and Varnishing; to make French Polish, Glues, 
Cements, and Compos’. ' ns; with numerous Receipts, useful to work 
men generally. B»- Stokes. Illustrated. A New Edition, with 
an Appendix upor „ench Polishing, Staining, Imitating, Varnishing, 

etc., etc. i2mo.$1.25 

STRENGTH AND OTHER PROPERTIES OF METALS; 
Reports of Experiments on the Strength and other Properties of 
Metals for Cannon. With a Description of the Machines for Testing 
Metals, and of the Classification of Cannon in service. By Officer? 
of the Ordnance Department, U. S. Army. By authority of the Secre- 
taryof War. Illustrated by 25 large steel plates. Quarto . $5.00 

SULLIVAN.—Protection to Native Industry. 

By Sir Edward Sullivan, Baronet, author of “Ten Chapters on 
Social Reforms.” 8vo. . . . - • • • $1.00 

SHERRATT.—The Elements of Hand-Railing: 

Simplified and Explained in Concise Problems that are Easily Under¬ 
stood. The whole illustrated with 'Thirty-eight Accurate and Origi¬ 
nal Plates, Founded on Geometrical Principles, and Showing how to 
Make Rail Without Centre Joints, Making Better Rail of the Same 
Material, with Half the l abor, and Showing How to Lay Out Stairs 
of all Kinds. By R. J. Sherratt. Folio. . . . $2.50 



26 HENRY CAREY BAIRl> & CO.’S CATALOGUE. 


SYME.—Outlines of an Industrial Science 
By David Syme. i2mo. . ... $2.oq 

TABLES SHOWING THE WEIGHT OF ROUND, 
SQUARE, AND FLAT BAR IRON, STEEL, ETC., 

By Measurement. Cloth ...... 63 

THALLNER.-Tool-Steel: 

A Concise Handbook on Tool-Steel in General. Its Treatment in 
the Operations of Forging, Annealing, Hardening, Tempering, etc., 
and the Appliances Therefor. By Otto Thallner, Manager in 
Chief of the Tool-Steel Works, Bismarckhiitte, Germany. From the 
German by William T. Brannt. Illustrated by 69 engravings. 
194 pages. 8vo. 1902. ...... $ 2.00 

TEMPLETON.—The Practical Examinator on Steam and thd 
Steam-Engine: 

With Instructive References relative thereto, arranged for the Use of 
Engineers, Students, and others. By William Templeton, En. 
gineer. T2mo. ........ $1.00 

THAUSING.—The Theory and Practice of the Preparation of 
Malt and the Fabrication of Beer: 

With especial reference to the Vienna Process of Brewing. Elab¬ 
orated from personal experience by Julius E. Thausing, Professor 
at the School for Brewers, and at the Agricultural Institute, Modling, 
near Vienna. Translated from the German by William T. Brannt, 
Thoroughly and elaborately edited, with much American matter, and 
according to the latest and most Scientific Practice, by A. Schwarz 
and Dr. A. H. Bauer. Illustrated by 140 Engravings. 8vo., 815 

pages. . $10.00 

THOMPSON.—Political Economy. With Especial Reference 
to the Industrial History of Nations : 

By Robert E. Thompson, M. A., Professor of Social Science in the 
University of Pennsylvania. i2mo. . . . . $1.50 

THOMSON.—Freight Charges Calculator: 

By Andrew Thomson, Freight Agent. 241110. . . $1.25 

TURNER’S (THE) COMPANION: 

Containing Instructions in Concentric, Elliptic, and Eccentric Turn, 
ing; also various Plates of Chucks, Tools, and Instruments; and 
Directions for using the Eccentric Cutter, Drill, Vertical Cutter, and 
Circular Rest; with Patterns and Instructions for working them, 

121110.$1.00 

TURNING: Specimens of Fancy Turning Executed on the 
Hand or Foot-Lathe: 

With Geometric, Oval, and Eccentric Chucks, and Elliptical Cutting 
Frame. By an Amateur. Illustrated by 30 exquisite Photographs. 
4 *°..(Scarce.) 





HENRY CAREY BAIRD & CO.’S CATALOGUE. 


2 7 


^AILE.—Galvanized-Iron Cornice-Worker’s Manual: 

Containing Instructions in Laying out the Different Mitres, and 
Making Patterns for all kinds of Plain and Circular Work. Also, 
Tables of Weights, Areas and Circumferences of Circles, and other 
Matter calculated to Benefit the Trade. By Charles A. Vaile. 
Illustrated by twenty-one plates. 4to. . , . .(Scarce.) 

VILLE.—On Artificial Manures : 

Their Chemical Selection and Scientific Application to Agriculture. 
A series of Lectures given at the Experimental Farm at Vincennes, 
during 1867 and 1874-75. By M. Georges Ville. Translated and 
Edited by William Crookes, F. R. S. Illustrated by thirty-one 

engravings. 8vo., 450 pages.#6.00 

VILLE.—The School of Chemical Manures : 

Or, Elementary Principles in the Use of Fertilizing Agents. From 
the French of M. Geo. Ville, by A. A. Fesquet, Chemist and En¬ 
gineer. With Illustrations. i2mo. .... #1.25 

VOGDES.—The Architect’s and Builder’s Pocket-Companion 
and Price-Book : 

Consisting of a Shoii but Comprehensive Epitome of Decimals, Duo¬ 
decimals, Geometry and Mensuration; with Tables of United States 
Measures, Sizes, Weights, Strengths, etc., of Iron, Wood, Stone, 
Brick, Cement and Concretes, Quantities of Materials in given Sizes 
and Dimensions of Wood, Brick and Stone; and full and complete 
Bills of Prices for Carpenter’s Work and Painting; also, Rules for 
Computing and Valuing Brick and Brick Work, Stone Work, Paint¬ 
ing, Plastering, with a Vocabulary of Technical Terms, etc. By 
Frank W. Vogdes, Architect, Indianapolis, Ind. Enlarged, revised, 
and corrected. In one volume, 368 pages, full-bound, pocket-book 
form, gilt edges.#2.00 

Cloth . . ....... 1.5a 

VAN CLEVE.—The English and American Mechanic : 

Comprising a Collection of Over Three Thousand Receipts, Rules, 
and Tables, designed for the Use of every Mechanic and Manufac¬ 
turer. By B. Frank Van Cleve. Illustrated. 500 pp. i2mo. $ 2.00 

VAN DER BURG.—School of Painting for the Imitation of 
Woods and Marbles: 

A Complete, Practical Treatise on the Art and Craft of Graining and 
Marbling with the Tools and Appliances. 36 plates. Folio, 12x20 

inches. . $6.00 

WVAHNSCHAFFE.—A Guide to the Scientific Examinatio» 
of Soils: 

Comprising Select Methods of Mechanical and Chemical A ialysk 
and Physical Investigation. Translated from the German of Dr. F. 
Wahnschaffe. With additions by William T. Brannt. IFlus 
trated by 25 engravings. 121110. 177 pages . . . $ 1-56 

WALTON.—Coal-Mining Described and Illustrated: 

By Thomas H. Walton, Mining Engineer. Illustrated by 24 largi 
and Haborate Plates, after Actual Workings and Apparatus. $ 2.00 








HENRY CAREY BAIRD & CO.’S CATALOGUE. 


2S 


WARE.—The Sugar Beet. 

Including a History of the Beet Sugar Industry in Europe, Varietid 
of the Sugar Beet, Examination, Soils, Tillage, Seeds and Sowing, 
Yield and Cost of Cultivation, Harvesting, Transportation, Conserva 
tion, Feeding Qualities of the Beet and of the Pulp, etc. By Lewis 
S. Ware, C. E., M. E. Illustrated by ninety engravings. 8vo. 

$ 3 - 5 ° 

WARN.—The Sheet-Metal Worker’s Instructor: 

For Zinc, Sheet-Iron, Copper, and Tin-Plate Workers, etc. Contain¬ 
ing a selection of Geometrical Problems; also, Practical and Simple 
Rules for Describing the various Patterns required in the different 
branches of the above Trades. By Reuben H. Warn, Practical 
Tin-Plate Worker. To which is added an Appendix, containing 
Instructions lor Boiler-Making, Mensuration of Surfaces and Solids, 
Rules for Calculating the Weights of different Figures of Iron and 
Steel, Tables of the Weights of Iron, Steel, etc. Illustrated by thirty 
two Plates and thirty-seven Wood Engravings. 8vo. . $2.50 

WARNER.—New Theorems, Tables, and Diagrams, for thft 
Computation of Earth-work: 

Designed for the use of Engineers in Preliminary and Final Estimates 
of Students in Engineering, and of Contractors and other non-profes¬ 
sional Computers. In two parts, with an Appendix. Part I. A Prac¬ 
tical Treatise; Part II. A Theoretical Treatise, and the Appendix, 
Containing Notes to the Rules and Examples of Part I.; Explana 
lions of the Construction of Scales, Tables, and Diagrams, and z 
Treatise upon Equivalent Square Bases and Equivalent Level Heights 
By John Warner, A. M., Mining and Mechanical Engineer. Illus- 
t -ated by 14 Plates. 8vo..$3.00 

WILSON.—Carpentry and Joinery : 

By John Wilson, Lecturer on Building Construction, Carpentry and 
Joinery, etc., in the Manchester Technical School. Third Edition, 
with 65 full-page plates, in flexible cover, oblong. . . (Scarce.) 

WATSON.—A Manual of the Hand-Lathe : 

Comprising Concise Directions for Working Metals of all kinds, 
Ivory, Bone, and Precious Woods ; Dyeing, Coloring, and French 
Polishing ; Inlaying by Veneers, and various methods practised to 
produce Elaborate work with Dispatch, and at Small Expense. By 
Egbert P. Watson. Author of “The Modern Practice of American 
Machinists and Engineers.” Illustrated by 78 engravings. $1.50 

WATSON.—The Modern Practice of American Machinists 
and Engineers : 

Including the Construction, Application, and Use of Drills, I athe 
Tools, Cutters for Boring Cylinders, and Hollow-work generally, with 
the most Economical Speed for the same ; the Results verified by 
Actual Practice at the Lathe, the Vise, and on the floor. Togethei 




HENRY CAREY BAIRD & CO.’S CATALOGUE. 


2 9 


vvith Workshop Management, Economy of Manufacture, the Steam 
Engine, Boilers, Gears, Belting, etc., etc. By Egbert P. Watson. 
Illustrated by eighty-six engravings. i2mo. . . . $2.50 

WATT. —The Art of Soap Making : 

A Practical Hand-Book of the Manufacture of Hard and Soft Soaps, 
Toilet Soaps, etc. Fifth Edition, Revised, to which is added an 
Appendix on Modern Candle Making. By Alexander Watt. 

Ill. 121110.#3.00 

WEATHERLY.—Treatise on the Art of Boiling Sugar, Crys¬ 
tallizing, Lozenge-making, Comfits, Gum Goods, 

And other processes for Confectionery, including Methods for Manu¬ 
facturing every Description of Raw and Refined Sugar Goods. A 
New and Enlarged Edition, with an Appendix on Cocoa, Chocolate, 
Chocolate Confections, etc. 196 pages, i2mo. (1903) . $1.5® 

WILL.— Tables of Qualitative Chemical Analysis : 

With an Introductory Chapter on the Course of Analysis. By Pro¬ 
fessor Heinrich Will, of Giessen, Germany. Third American, 
from the eleventh German edition. Edited by Charles F. Himes, 
Ph. D., Professor of Natural Science, Dickinson College, Carlisle, 

Pa. 8vo.$1.50 

WILLIAMS. —On Heat and Steam : 

Embracing New Views of Vaporization, Condensation and Explo¬ 
sion. By Charles Wye Williams, A. I. C. E. Illustrated. 8vo. 

$2.50 

WILSON. —First Principles of Political Economy: 

With Reference to Statesmanship and the Progress of Civilization. 
By Professor W. D. Wilson, of the Cornell University. A new and 
revised edition. i2mo. ...... $1.50 

WILSON.—The Practical Tool-Maker and Designer: 

A Treatise upon the Designing of Tools and Fixtures for Machine 
Tools and Metal Working Machinery, Comprising Modern Examples 
of Machines with Fundamental Designs for Tools for the Actual Pro¬ 
duction of the work; Together with Special Reference to a Set of 
Tools for Machining the Various Parts of a Bicycle. Illustrated by 
189 engravings. 1898..$2.50 

CONTENTS: Introductory. Chapter I. Modern Tool Room and Equipment. 
II. Files, Their Use and Abuse. III. Steel and Tempering. IV. Making Jigs. 
V. Milling Machine Fixtures. VI. Tools and Fixtures for Screw Machines. VII. 
Broaching. VIII. Punches and Dies for Cutting and Drop Press. IX.Toolsfor 
Hollow-Ware. X. Embossing: Metal, Coin, and Stamped Sheet-Metal Orna¬ 
ments. XL Drop Forging. XII. Solid Drawn Shells or Ferrules, Cupping or 
Cutting, and Drawing; Breaking Down Shells. XIII. Annealing, Pickling,and 
Cleaning, XIV. Tools for Draw Bench. XV. Cutting and Assembling Pieces 
by Means of Ratchet Dial Plates at One Operation. XVI. TheHeader. XVII. 
Tools for Fox Lathe. XVIII. Suggestions for a Set of Tools for Machining the 
Various Parts of a Bicycle. XIX. The Plater’s Dynamo. XX. Conclusion— 
With a Few Random Ideas. Apperidix. Index. 

WOODS—Compound Locomotives: 

By Arthur Tannatt Woods. Second edition, revised and enlarged 
by David Leonard Barnes, A. M., C. E. 8vo. 330 pp. $3 -00 





30 HENRY CAREY BAIRD & CO.’S CATALOGUE. 


WOHLER.—A Hand-Book of Mineral Analysis: 

Bv F. WoHLER, Professor of Chemistry in the University of Gottin¬ 
gen. Edited by Henry B. Nason, Professor of Chemistry in the 
Renssalaer Polytechnic Institute, Troy, New York. Illustrated. 
!2mo. #2.50 

WORSSAM.—On Mechanical Saws: 

From the Transactions of the Society of Engineers. 1869. By S. W. 
Worssam, Jr. Illustrated by eighteen large plates. 8vo. $1.5° 


RECENT ADDITIONS. 

BRANNT.—Varnishes, Lacquers, Printing Inks and Sealing- 

Waxes : 

Their Raw Materials and their Manufacture, to which is added the 
Art of Varnishing and Lacquering, including the Preparation of Put¬ 
ties and of Stains for Wood, Ivory, Bone, Horn, and Leather. By 
William T. Brannt. Illustrated by 39 Engravings, 338 pages. 
i2mo. .......... $3.00 

BRANNT.—The Practical Dry Cleaner, Scourer, and Gar¬ 
ment Dyer: 

Comprising Dry or Chemical Cleaning; Purification of Benzine; Re¬ 
moving Stains or Spotting; Wet Cleaning; Finishing Cleaned Fabrics; 
Cleaning and Dyeing Furs, Skins, Rugs, and Mats; Cleaning and 
Dyeing Feathers; Bleaching and Dyeing Straw Hats; Cleaning and 
Dyeing Gloves; Garment Dyeing; Stripping; Analysis of Textile 
Fabrics. Edited by William T. Brannt, Editor of “The Techno- 
Chemical Receipt Book.” Third Edition, Revised and Enlarged. 

Illustrated by Twenty-Three Engravings. $2 50 

BRANNT.—Petroleum. 

its History, Origin, Occurrence, Production, Physical and Chemical 
Constitution, Technology, Examination and Uses; Together with 
the Occurrence and Uses of Natural Gas. Edited chiefly from the 
German of Prof. Hans Hoefer and Dr. Alexander Veith, by Wm. 
T. Brannt. Illustrated by 3 Plates and 284 Engravings. 743 pD. 
8 vo. $ 10.00 

BRANNT.—A Practical Treatise on the Manufacture of Vine¬ 
gar and Acetates, Cider, and Fruit-Wines: 

Preservation of Fruits and Vegetables by Canning and Evaporation; 
Preparation of Fruit-Butters, Jellies, Marmalades, Catchups, Pickles, 
Mustards, etc. Edited from various sources. By William T. 
Brannt. Illustrated by 79 Engravings. 479 pp. 8vo, $6.00 

BRANNT.—The Metal Worker’s Handy-Book of Receipts 
and Processes: 

Being a Collection of Chemical Formulas and Practical Manipula¬ 
tions for the working of all Metals; including the Decoration and 
Beautifying of Articles Manufactured therefrom, as well as their 
Preservation. Edited from various sources. By William T. 
Brannt. Illustrated. i2mo. $2,50 








HENRY CAREY BAIRD & CO.’S CATALOGUE. 


31 

DsEITE. —A Practical Treatise on the Manufacture of Per¬ 
fumery : 

Comprising directions for making all Kinds of Perfumes, Sachef 
Powders, Fumigating Materials, Dentifrices, Cosmetics, etc., with a 
full account of the Volatile Oils, Balsams, Resins, and other Natural 
and Artificial Perfume-substances, including the Manufacture of 
Fruit Ethers, and tests of their purity. By Dr. C. Deite. assisted 
by L. Borchert, F. Eichbaum, E. Kugler, H. Toeffner, and 
other experts. From the German, by Wm. T. Brannt. 28 Engrav¬ 
ings. 358 pages. 8vo. .. I3.00 

EDWARDS.—American Marine Engineer, Theoretical and 
Practical: 

With Examples of the latest and most approved American Practice. 
By Emory Edwards. 85 illustrations. i2mo. . . $2.00 


EDWARDS.—900 Examination Questions and Answers: 

For Engineers and Firemen (Land and Marine) who desire to ob¬ 
tain a United States Government or State License. Pocket-book 

form, gilt edge.#1.50 

FLEMMING.—Practical Tanning: 

A Handbook of Modern Processes, Receipts, and Suggestions for the 
Treatment of Hides, Skins, and Pelts of Every Description. By 
Lewis A. Flemming. American Tanner. 472 pp. 8vo. ( 1903) $4.00. 

POSSELT.—The Jacquard Machine Analysed and Explained: 

With an Appendix on the Preparation of Jacquard Cards, and 
Practical Hints to Learners of Jacquard Designing. By E. A. 
Posselt. With 230 illustrations and numerous diagrams. 127 pp. 
4to.#3-00 


POSSELT.—Recent Improvements in Textile Machinery, 
Part III: 

Processes Required for Converting Wool, Cotton, Silk, from Fibre 
to Finished Fabric, Covering both Woven and Knit Goods ; Con¬ 
struction of the most Modern Improvements in Preparatory Machin¬ 
ery, Carding, Combing, Drawing, and Spinning Machinery, Winding, 
Warping, Slashing Machinery Looms, Machinery for Knit Goods, 
Dye Stuffs, Chemicals, Soaps, Latest Improved Accessories Relat¬ 
ing to Construction and Equipment of Modern Textile Manufactur¬ 
ing Plants. By E. A. Posselt. Completel" Illustrated. 4to. 

$ 7 - 5 ° 


RICH.—Artistic Horse-Shoeing: 

A Practical and Scientific Treatise, giving Improved Methods of 
Shoeing, with Special Directions for Shaping Shoes to Cure Different 
Diseases of the Foot, and for the Correction of Faulty Action in 
Trotters. By George E. Rich. 62 Illustrations. 153 pa^es 
.. - 2 * 00 




32 HENRY CAREY BAIRD & CO.’S CATALOGUE. 


RICHARDSON. --Practical Blacksmithing: 

A Collection of Articles Contributed at Different Times by Skilled 
Workmen to the columns of “ The Blacksmith and Wheelwright,” 
and Covering nearly the Whole Range of Blacksmithing, from the 
Simplest Job of Work to some of the Most Complex Forgings. 


Compiled and Edited by M. T. Richardson. 

Vol. I. 210 Illustrations. 224 pages. l2mo. • • $1.00 

Vol. II. 230 Illustrations. 262 pages. i2mo. • • $1.00 

Vol. III. 390 Illustrations. 307 pages. i2mo, , . $1.00 

Vol. IV. 226 Illustrations. 276 pages. l2mo. , . #1.00 

RICHARDSON. —The Practical Horseshoer: 


Being a Collection of Articles on Horseshoeing in all its Branches* 
which have appeared from time to time in the columns of “'1 he 1 
Blacksmith and Wheelwright,” etc. Compiled and edited by M. T. 
Richardson. 174 illustrations. . . . . . #1.00 

ROPER.—Instructions and Suggestions for Engineers and 
Firemen: 

By Stephen Roper, Engineer. i8mo. Morocco . #2.00 

ROPER.—The Steam Boiler: Its Care and Management: 

By Stephen Roper, Engineer. 12mo., tuck, gilt edges. $2.00 
ROPER.—The Young Engineer’s Own Book: 

Containing an Explanation of the Principle and Theories on which 
the Steam Engine as a Prime Mover is Based. By Stephen Roper, 
Engineer. 160 illustrations, 363 pages. i8mo., tuck . $2.50 

S.OSE.—Modern Steam-Engines: 

An Elementary Treatise upon the Steam-Engine, written in Plain 
language; for Use in the Workshop as well as in the Drawing Office. 
Giving Full Explanation i of the Construction of Modern Steam. 
Engines: Including Diagrams showing their Actual operation. To¬ 
gether with Complete but Simple Explanations of the operations of 
Various Kinds of Valves, Valve Motions, and Link Motions, etc., 
thereby Enabling the Ordinary Engineer to clearly Understand the 
Principles involved in their Construction and Use, and to Plot out 
their Movements upon the Drawing Board. By Joshua Rose. M. E. 
Illustrated by 422 engravings. Revised. 358 pp. . . $6.00 

ROSE.—Steam Boilers: 

A Practical Treatise on Boiler Construction and Examination, for the 
Use of Practical Boiler Makers, Boiler Users, and Inspectors; and 
embracing m plain figures all the calculations necessary in Designing 
or Classifying Steam Boilers. By Joshua Rose, M. E. Illustrated 
by 73 engravings. 250 pages. 8vo. .... $2.50 

SCHRIBER.—The Complete Carriage and Wagon Painter: 

A Concise Compendium of the Art of Painting Carriages, Wagons, 
and Sleighs, embracing Full Directions in all the Various Branches, 
including Lettering, Scrolling, Ornamenting, Striping, Varnishing, 
and Coloring, with numerous Recipes for Mixing Colors. 73 Illus¬ 
trations. 177 pp. i2mo. Jioft 















































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